1 /* $NetBSD: uvm_map.c,v 1.387 2021/04/17 01:53:58 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94 37 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp 38 * 39 * 40 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 41 * All rights reserved. 42 * 43 * Permission to use, copy, modify and distribute this software and 44 * its documentation is hereby granted, provided that both the copyright 45 * notice and this permission notice appear in all copies of the 46 * software, derivative works or modified versions, and any portions 47 * thereof, and that both notices appear in supporting documentation. 48 * 49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 52 * 53 * Carnegie Mellon requests users of this software to return to 54 * 55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 56 * School of Computer Science 57 * Carnegie Mellon University 58 * Pittsburgh PA 15213-3890 59 * 60 * any improvements or extensions that they make and grant Carnegie the 61 * rights to redistribute these changes. 62 */ 63 64 /* 65 * uvm_map.c: uvm map operations 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.387 2021/04/17 01:53:58 mrg Exp $"); 70 71 #include "opt_ddb.h" 72 #include "opt_pax.h" 73 #include "opt_uvmhist.h" 74 #include "opt_uvm.h" 75 #include "opt_sysv.h" 76 77 #include <sys/param.h> 78 #include <sys/systm.h> 79 #include <sys/mman.h> 80 #include <sys/proc.h> 81 #include <sys/pool.h> 82 #include <sys/kernel.h> 83 #include <sys/mount.h> 84 #include <sys/pax.h> 85 #include <sys/vnode.h> 86 #include <sys/filedesc.h> 87 #include <sys/lockdebug.h> 88 #include <sys/atomic.h> 89 #include <sys/sysctl.h> 90 #ifndef __USER_VA0_IS_SAFE 91 #include <sys/kauth.h> 92 #include "opt_user_va0_disable_default.h" 93 #endif 94 95 #include <sys/shm.h> 96 97 #include <uvm/uvm.h> 98 #include <uvm/uvm_readahead.h> 99 100 #if defined(DDB) || defined(DEBUGPRINT) 101 #include <uvm/uvm_ddb.h> 102 #endif 103 104 #ifdef UVMHIST 105 #ifndef UVMHIST_MAPHIST_SIZE 106 #define UVMHIST_MAPHIST_SIZE 100 107 #endif 108 #ifndef UVMHIST_PDHIST_SIZE 109 #define UVMHIST_PDHIST_SIZE 100 110 #endif 111 static struct kern_history_ent maphistbuf[UVMHIST_MAPHIST_SIZE]; 112 UVMHIST_DEFINE(maphist) = UVMHIST_INITIALIZER(maphist, maphistbuf); 113 #endif 114 115 #if !defined(UVMMAP_COUNTERS) 116 117 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 118 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 119 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 120 121 #else /* defined(UVMMAP_NOCOUNTERS) */ 122 123 #include <sys/evcnt.h> 124 #define UVMMAP_EVCNT_DEFINE(name) \ 125 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 126 "uvmmap", #name); \ 127 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 128 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 129 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 130 131 #endif /* defined(UVMMAP_NOCOUNTERS) */ 132 133 UVMMAP_EVCNT_DEFINE(ubackmerge) 134 UVMMAP_EVCNT_DEFINE(uforwmerge) 135 UVMMAP_EVCNT_DEFINE(ubimerge) 136 UVMMAP_EVCNT_DEFINE(unomerge) 137 UVMMAP_EVCNT_DEFINE(kbackmerge) 138 UVMMAP_EVCNT_DEFINE(kforwmerge) 139 UVMMAP_EVCNT_DEFINE(kbimerge) 140 UVMMAP_EVCNT_DEFINE(knomerge) 141 UVMMAP_EVCNT_DEFINE(map_call) 142 UVMMAP_EVCNT_DEFINE(mlk_call) 143 UVMMAP_EVCNT_DEFINE(mlk_hint) 144 UVMMAP_EVCNT_DEFINE(mlk_tree) 145 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 146 147 const char vmmapbsy[] = "vmmapbsy"; 148 149 /* 150 * cache for vmspace structures. 151 */ 152 153 static struct pool_cache uvm_vmspace_cache; 154 155 /* 156 * cache for dynamically-allocated map entries. 157 */ 158 159 static struct pool_cache uvm_map_entry_cache; 160 161 #ifdef PMAP_GROWKERNEL 162 /* 163 * This global represents the end of the kernel virtual address 164 * space. If we want to exceed this, we must grow the kernel 165 * virtual address space dynamically. 166 * 167 * Note, this variable is locked by kernel_map's lock. 168 */ 169 vaddr_t uvm_maxkaddr; 170 #endif 171 172 #ifndef __USER_VA0_IS_SAFE 173 #ifndef __USER_VA0_DISABLE_DEFAULT 174 #define __USER_VA0_DISABLE_DEFAULT 1 175 #endif 176 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 177 #undef __USER_VA0_DISABLE_DEFAULT 178 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 179 #endif 180 int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 181 #endif 182 183 /* 184 * macros 185 */ 186 187 /* 188 * uvm_map_align_va: round down or up virtual address 189 */ 190 static __inline void 191 uvm_map_align_va(vaddr_t *vap, vsize_t align, int topdown) 192 { 193 194 KASSERT(powerof2(align)); 195 196 if (align != 0 && (*vap & (align - 1)) != 0) { 197 if (topdown) 198 *vap = rounddown2(*vap, align); 199 else 200 *vap = roundup2(*vap, align); 201 } 202 } 203 204 /* 205 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 206 */ 207 extern struct vm_map *pager_map; 208 209 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 210 prot, maxprot, inh, adv, wire) \ 211 ((ent)->etype == (type) && \ 212 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE)) == 0 && \ 213 (ent)->object.uvm_obj == (uobj) && \ 214 (ent)->protection == (prot) && \ 215 (ent)->max_protection == (maxprot) && \ 216 (ent)->inheritance == (inh) && \ 217 (ent)->advice == (adv) && \ 218 (ent)->wired_count == (wire)) 219 220 /* 221 * uvm_map_entry_link: insert entry into a map 222 * 223 * => map must be locked 224 */ 225 #define uvm_map_entry_link(map, after_where, entry) do { \ 226 uvm_mapent_check(entry); \ 227 (map)->nentries++; \ 228 (entry)->prev = (after_where); \ 229 (entry)->next = (after_where)->next; \ 230 (entry)->prev->next = (entry); \ 231 (entry)->next->prev = (entry); \ 232 uvm_rb_insert((map), (entry)); \ 233 } while (/*CONSTCOND*/ 0) 234 235 /* 236 * uvm_map_entry_unlink: remove entry from a map 237 * 238 * => map must be locked 239 */ 240 #define uvm_map_entry_unlink(map, entry) do { \ 241 KASSERT((entry) != (map)->first_free); \ 242 KASSERT((entry) != (map)->hint); \ 243 uvm_mapent_check(entry); \ 244 (map)->nentries--; \ 245 (entry)->next->prev = (entry)->prev; \ 246 (entry)->prev->next = (entry)->next; \ 247 uvm_rb_remove((map), (entry)); \ 248 } while (/*CONSTCOND*/ 0) 249 250 /* 251 * SAVE_HINT: saves the specified entry as the hint for future lookups. 252 * 253 * => map need not be locked. 254 */ 255 #define SAVE_HINT(map, check, value) do { \ 256 if ((map)->hint == (check)) \ 257 (map)->hint = (value); \ 258 } while (/*CONSTCOND*/ 0) 259 260 /* 261 * clear_hints: ensure that hints don't point to the entry. 262 * 263 * => map must be write-locked. 264 */ 265 static void 266 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 267 { 268 269 SAVE_HINT(map, ent, ent->prev); 270 if (map->first_free == ent) { 271 map->first_free = ent->prev; 272 } 273 } 274 275 /* 276 * VM_MAP_RANGE_CHECK: check and correct range 277 * 278 * => map must at least be read locked 279 */ 280 281 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 282 if (start < vm_map_min(map)) \ 283 start = vm_map_min(map); \ 284 if (end > vm_map_max(map)) \ 285 end = vm_map_max(map); \ 286 if (start > end) \ 287 start = end; \ 288 } while (/*CONSTCOND*/ 0) 289 290 /* 291 * local prototypes 292 */ 293 294 static struct vm_map_entry * 295 uvm_mapent_alloc(struct vm_map *, int); 296 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 297 static void uvm_mapent_free(struct vm_map_entry *); 298 #if defined(DEBUG) 299 static void _uvm_mapent_check(const struct vm_map_entry *, int); 300 #define uvm_mapent_check(map) _uvm_mapent_check(map, __LINE__) 301 #else /* defined(DEBUG) */ 302 #define uvm_mapent_check(e) /* nothing */ 303 #endif /* defined(DEBUG) */ 304 305 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 306 static void uvm_map_reference_amap(struct vm_map_entry *, int); 307 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 308 int, struct vm_map_entry *); 309 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 310 311 int _uvm_map_sanity(struct vm_map *); 312 int _uvm_tree_sanity(struct vm_map *); 313 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 314 315 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 316 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 317 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 318 #define PARENT_ENTRY(map, entry) \ 319 (ROOT_ENTRY(map) == (entry) \ 320 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 321 322 /* 323 * These get filled in if/when SYSVSHM shared memory code is loaded 324 * 325 * We do this with function pointers rather the #ifdef SYSVSHM so the 326 * SYSVSHM code can be loaded and unloaded 327 */ 328 void (*uvm_shmexit)(struct vmspace *) = NULL; 329 void (*uvm_shmfork)(struct vmspace *, struct vmspace *) = NULL; 330 331 static int 332 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey) 333 { 334 const struct vm_map_entry *eparent = nparent; 335 const struct vm_map_entry *ekey = nkey; 336 337 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 338 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 339 340 if (eparent->start < ekey->start) 341 return -1; 342 if (eparent->end >= ekey->start) 343 return 1; 344 return 0; 345 } 346 347 static int 348 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey) 349 { 350 const struct vm_map_entry *eparent = nparent; 351 const vaddr_t va = *(const vaddr_t *) vkey; 352 353 if (eparent->start < va) 354 return -1; 355 if (eparent->end >= va) 356 return 1; 357 return 0; 358 } 359 360 static const rb_tree_ops_t uvm_map_tree_ops = { 361 .rbto_compare_nodes = uvm_map_compare_nodes, 362 .rbto_compare_key = uvm_map_compare_key, 363 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node), 364 .rbto_context = NULL 365 }; 366 367 /* 368 * uvm_rb_gap: return the gap size between our entry and next entry. 369 */ 370 static inline vsize_t 371 uvm_rb_gap(const struct vm_map_entry *entry) 372 { 373 374 KASSERT(entry->next != NULL); 375 return entry->next->start - entry->end; 376 } 377 378 static vsize_t 379 uvm_rb_maxgap(const struct vm_map_entry *entry) 380 { 381 struct vm_map_entry *child; 382 vsize_t maxgap = entry->gap; 383 384 /* 385 * We need maxgap to be the largest gap of us or any of our 386 * descendents. Since each of our children's maxgap is the 387 * cached value of their largest gap of themselves or their 388 * descendents, we can just use that value and avoid recursing 389 * down the tree to calculate it. 390 */ 391 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 392 maxgap = child->maxgap; 393 394 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 395 maxgap = child->maxgap; 396 397 return maxgap; 398 } 399 400 static void 401 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 402 { 403 struct vm_map_entry *parent; 404 405 KASSERT(entry->gap == uvm_rb_gap(entry)); 406 entry->maxgap = uvm_rb_maxgap(entry); 407 408 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 409 struct vm_map_entry *brother; 410 vsize_t maxgap = parent->gap; 411 unsigned int which; 412 413 KDASSERT(parent->gap == uvm_rb_gap(parent)); 414 if (maxgap < entry->maxgap) 415 maxgap = entry->maxgap; 416 /* 417 * Since we work towards the root, we know entry's maxgap 418 * value is OK, but its brothers may now be out-of-date due 419 * to rebalancing. So refresh it. 420 */ 421 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER; 422 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which]; 423 if (brother != NULL) { 424 KDASSERT(brother->gap == uvm_rb_gap(brother)); 425 brother->maxgap = uvm_rb_maxgap(brother); 426 if (maxgap < brother->maxgap) 427 maxgap = brother->maxgap; 428 } 429 430 parent->maxgap = maxgap; 431 entry = parent; 432 } 433 } 434 435 static void 436 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 437 { 438 struct vm_map_entry *ret __diagused; 439 440 entry->gap = entry->maxgap = uvm_rb_gap(entry); 441 if (entry->prev != &map->header) 442 entry->prev->gap = uvm_rb_gap(entry->prev); 443 444 ret = rb_tree_insert_node(&map->rb_tree, entry); 445 KASSERTMSG(ret == entry, 446 "uvm_rb_insert: map %p: duplicate entry %p", map, ret); 447 448 /* 449 * If the previous entry is not our immediate left child, then it's an 450 * ancestor and will be fixed up on the way to the root. We don't 451 * have to check entry->prev against &map->header since &map->header 452 * will never be in the tree. 453 */ 454 uvm_rb_fixup(map, 455 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 456 } 457 458 static void 459 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 460 { 461 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 462 463 /* 464 * If we are removing an interior node, then an adjacent node will 465 * be used to replace its position in the tree. Therefore we will 466 * need to fixup the tree starting at the parent of the replacement 467 * node. So record their parents for later use. 468 */ 469 if (entry->prev != &map->header) 470 prev_parent = PARENT_ENTRY(map, entry->prev); 471 if (entry->next != &map->header) 472 next_parent = PARENT_ENTRY(map, entry->next); 473 474 rb_tree_remove_node(&map->rb_tree, entry); 475 476 /* 477 * If the previous node has a new parent, fixup the tree starting 478 * at the previous node's old parent. 479 */ 480 if (entry->prev != &map->header) { 481 /* 482 * Update the previous entry's gap due to our absence. 483 */ 484 entry->prev->gap = uvm_rb_gap(entry->prev); 485 uvm_rb_fixup(map, entry->prev); 486 if (prev_parent != NULL 487 && prev_parent != entry 488 && prev_parent != PARENT_ENTRY(map, entry->prev)) 489 uvm_rb_fixup(map, prev_parent); 490 } 491 492 /* 493 * If the next node has a new parent, fixup the tree starting 494 * at the next node's old parent. 495 */ 496 if (entry->next != &map->header) { 497 uvm_rb_fixup(map, entry->next); 498 if (next_parent != NULL 499 && next_parent != entry 500 && next_parent != PARENT_ENTRY(map, entry->next)) 501 uvm_rb_fixup(map, next_parent); 502 } 503 } 504 505 #if defined(DEBUG) 506 int uvm_debug_check_map = 0; 507 int uvm_debug_check_rbtree = 0; 508 #define uvm_map_check(map, name) \ 509 _uvm_map_check((map), (name), __FILE__, __LINE__) 510 static void 511 _uvm_map_check(struct vm_map *map, const char *name, 512 const char *file, int line) 513 { 514 515 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 516 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 517 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 518 name, map, file, line); 519 } 520 } 521 #else /* defined(DEBUG) */ 522 #define uvm_map_check(map, name) /* nothing */ 523 #endif /* defined(DEBUG) */ 524 525 #if defined(DEBUG) || defined(DDB) 526 int 527 _uvm_map_sanity(struct vm_map *map) 528 { 529 bool first_free_found = false; 530 bool hint_found = false; 531 const struct vm_map_entry *e; 532 struct vm_map_entry *hint = map->hint; 533 534 e = &map->header; 535 for (;;) { 536 if (map->first_free == e) { 537 first_free_found = true; 538 } else if (!first_free_found && e->next->start > e->end) { 539 printf("first_free %p should be %p\n", 540 map->first_free, e); 541 return -1; 542 } 543 if (hint == e) { 544 hint_found = true; 545 } 546 547 e = e->next; 548 if (e == &map->header) { 549 break; 550 } 551 } 552 if (!first_free_found) { 553 printf("stale first_free\n"); 554 return -1; 555 } 556 if (!hint_found) { 557 printf("stale hint\n"); 558 return -1; 559 } 560 return 0; 561 } 562 563 int 564 _uvm_tree_sanity(struct vm_map *map) 565 { 566 struct vm_map_entry *tmp, *trtmp; 567 int n = 0, i = 1; 568 569 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 570 if (tmp->gap != uvm_rb_gap(tmp)) { 571 printf("%d/%d gap %#lx != %#lx %s\n", 572 n + 1, map->nentries, 573 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 574 tmp->next == &map->header ? "(last)" : ""); 575 goto error; 576 } 577 /* 578 * If any entries are out of order, tmp->gap will be unsigned 579 * and will likely exceed the size of the map. 580 */ 581 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 582 printf("too large gap %zu\n", (size_t)tmp->gap); 583 goto error; 584 } 585 n++; 586 } 587 588 if (n != map->nentries) { 589 printf("nentries: %d vs %d\n", n, map->nentries); 590 goto error; 591 } 592 593 trtmp = NULL; 594 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 595 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 596 printf("maxgap %#lx != %#lx\n", 597 (ulong)tmp->maxgap, 598 (ulong)uvm_rb_maxgap(tmp)); 599 goto error; 600 } 601 if (trtmp != NULL && trtmp->start >= tmp->start) { 602 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 603 trtmp->start, tmp->start); 604 goto error; 605 } 606 607 trtmp = tmp; 608 } 609 610 for (tmp = map->header.next; tmp != &map->header; 611 tmp = tmp->next, i++) { 612 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT); 613 if (trtmp == NULL) 614 trtmp = &map->header; 615 if (tmp->prev != trtmp) { 616 printf("lookup: %d: %p->prev=%p: %p\n", 617 i, tmp, tmp->prev, trtmp); 618 goto error; 619 } 620 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT); 621 if (trtmp == NULL) 622 trtmp = &map->header; 623 if (tmp->next != trtmp) { 624 printf("lookup: %d: %p->next=%p: %p\n", 625 i, tmp, tmp->next, trtmp); 626 goto error; 627 } 628 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start); 629 if (trtmp != tmp) { 630 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 631 PARENT_ENTRY(map, tmp)); 632 goto error; 633 } 634 } 635 636 return (0); 637 error: 638 return (-1); 639 } 640 #endif /* defined(DEBUG) || defined(DDB) */ 641 642 /* 643 * vm_map_lock: acquire an exclusive (write) lock on a map. 644 * 645 * => The locking protocol provides for guaranteed upgrade from shared -> 646 * exclusive by whichever thread currently has the map marked busy. 647 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 648 * other problems, it defeats any fairness guarantees provided by RW 649 * locks. 650 */ 651 652 void 653 vm_map_lock(struct vm_map *map) 654 { 655 656 for (;;) { 657 rw_enter(&map->lock, RW_WRITER); 658 if (map->busy == NULL || map->busy == curlwp) { 659 break; 660 } 661 mutex_enter(&map->misc_lock); 662 rw_exit(&map->lock); 663 if (map->busy != NULL) { 664 cv_wait(&map->cv, &map->misc_lock); 665 } 666 mutex_exit(&map->misc_lock); 667 } 668 map->timestamp++; 669 } 670 671 /* 672 * vm_map_lock_try: try to lock a map, failing if it is already locked. 673 */ 674 675 bool 676 vm_map_lock_try(struct vm_map *map) 677 { 678 679 if (!rw_tryenter(&map->lock, RW_WRITER)) { 680 return false; 681 } 682 if (map->busy != NULL) { 683 rw_exit(&map->lock); 684 return false; 685 } 686 map->timestamp++; 687 return true; 688 } 689 690 /* 691 * vm_map_unlock: release an exclusive lock on a map. 692 */ 693 694 void 695 vm_map_unlock(struct vm_map *map) 696 { 697 698 KASSERT(rw_write_held(&map->lock)); 699 KASSERT(map->busy == NULL || map->busy == curlwp); 700 rw_exit(&map->lock); 701 } 702 703 /* 704 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 705 * want an exclusive lock. 706 */ 707 708 void 709 vm_map_unbusy(struct vm_map *map) 710 { 711 712 KASSERT(map->busy == curlwp); 713 714 /* 715 * Safe to clear 'busy' and 'waiters' with only a read lock held: 716 * 717 * o they can only be set with a write lock held 718 * o writers are blocked out with a read or write hold 719 * o at any time, only one thread owns the set of values 720 */ 721 mutex_enter(&map->misc_lock); 722 map->busy = NULL; 723 cv_broadcast(&map->cv); 724 mutex_exit(&map->misc_lock); 725 } 726 727 /* 728 * vm_map_lock_read: acquire a shared (read) lock on a map. 729 */ 730 731 void 732 vm_map_lock_read(struct vm_map *map) 733 { 734 735 rw_enter(&map->lock, RW_READER); 736 } 737 738 /* 739 * vm_map_unlock_read: release a shared lock on a map. 740 */ 741 742 void 743 vm_map_unlock_read(struct vm_map *map) 744 { 745 746 rw_exit(&map->lock); 747 } 748 749 /* 750 * vm_map_busy: mark a map as busy. 751 * 752 * => the caller must hold the map write locked 753 */ 754 755 void 756 vm_map_busy(struct vm_map *map) 757 { 758 759 KASSERT(rw_write_held(&map->lock)); 760 KASSERT(map->busy == NULL); 761 762 map->busy = curlwp; 763 } 764 765 /* 766 * vm_map_locked_p: return true if the map is write locked. 767 * 768 * => only for debug purposes like KASSERTs. 769 * => should not be used to verify that a map is not locked. 770 */ 771 772 bool 773 vm_map_locked_p(struct vm_map *map) 774 { 775 776 return rw_write_held(&map->lock); 777 } 778 779 /* 780 * uvm_mapent_alloc: allocate a map entry 781 */ 782 783 static struct vm_map_entry * 784 uvm_mapent_alloc(struct vm_map *map, int flags) 785 { 786 struct vm_map_entry *me; 787 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 788 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 789 790 me = pool_cache_get(&uvm_map_entry_cache, pflags); 791 if (__predict_false(me == NULL)) { 792 return NULL; 793 } 794 me->flags = 0; 795 796 UVMHIST_LOG(maphist, "<- new entry=%#jx [kentry=%jd]", (uintptr_t)me, 797 (map == kernel_map), 0, 0); 798 return me; 799 } 800 801 /* 802 * uvm_mapent_free: free map entry 803 */ 804 805 static void 806 uvm_mapent_free(struct vm_map_entry *me) 807 { 808 UVMHIST_FUNC(__func__); 809 UVMHIST_CALLARGS(maphist,"<- freeing map entry=%#jx [flags=%#jx]", 810 (uintptr_t)me, me->flags, 0, 0); 811 pool_cache_put(&uvm_map_entry_cache, me); 812 } 813 814 /* 815 * uvm_mapent_copy: copy a map entry, preserving flags 816 */ 817 818 static inline void 819 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 820 { 821 822 memcpy(dst, src, sizeof(*dst)); 823 dst->flags = 0; 824 } 825 826 #if defined(DEBUG) 827 static void 828 _uvm_mapent_check(const struct vm_map_entry *entry, int line) 829 { 830 831 if (entry->start >= entry->end) { 832 goto bad; 833 } 834 if (UVM_ET_ISOBJ(entry)) { 835 if (entry->object.uvm_obj == NULL) { 836 goto bad; 837 } 838 } else if (UVM_ET_ISSUBMAP(entry)) { 839 if (entry->object.sub_map == NULL) { 840 goto bad; 841 } 842 } else { 843 if (entry->object.uvm_obj != NULL || 844 entry->object.sub_map != NULL) { 845 goto bad; 846 } 847 } 848 if (!UVM_ET_ISOBJ(entry)) { 849 if (entry->offset != 0) { 850 goto bad; 851 } 852 } 853 854 return; 855 856 bad: 857 panic("%s: bad entry %p, line %d", __func__, entry, line); 858 } 859 #endif /* defined(DEBUG) */ 860 861 /* 862 * uvm_map_entry_unwire: unwire a map entry 863 * 864 * => map should be locked by caller 865 */ 866 867 static inline void 868 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 869 { 870 871 entry->wired_count = 0; 872 uvm_fault_unwire_locked(map, entry->start, entry->end); 873 } 874 875 876 /* 877 * wrapper for calling amap_ref() 878 */ 879 static inline void 880 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 881 { 882 883 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 884 (entry->end - entry->start) >> PAGE_SHIFT, flags); 885 } 886 887 888 /* 889 * wrapper for calling amap_unref() 890 */ 891 static inline void 892 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 893 { 894 895 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 896 (entry->end - entry->start) >> PAGE_SHIFT, flags); 897 } 898 899 900 /* 901 * uvm_map_init: init mapping system at boot time. 902 */ 903 904 void 905 uvm_map_init(void) 906 { 907 /* 908 * first, init logging system. 909 */ 910 911 UVMHIST_FUNC(__func__); 912 UVMHIST_LINK_STATIC(maphist); 913 UVMHIST_LINK_STATIC(pdhist); 914 UVMHIST_CALLED(maphist); 915 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 916 917 /* 918 * initialize the global lock for kernel map entry. 919 */ 920 921 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 922 } 923 924 /* 925 * uvm_map_init_caches: init mapping system caches. 926 */ 927 void 928 uvm_map_init_caches(void) 929 { 930 /* 931 * initialize caches. 932 */ 933 934 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 935 coherency_unit, 0, PR_LARGECACHE, "vmmpepl", NULL, IPL_NONE, NULL, 936 NULL, NULL); 937 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 938 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 939 } 940 941 /* 942 * clippers 943 */ 944 945 /* 946 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 947 */ 948 949 static void 950 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 951 vaddr_t splitat) 952 { 953 vaddr_t adj; 954 955 KASSERT(entry1->start < splitat); 956 KASSERT(splitat < entry1->end); 957 958 adj = splitat - entry1->start; 959 entry1->end = entry2->start = splitat; 960 961 if (entry1->aref.ar_amap) { 962 amap_splitref(&entry1->aref, &entry2->aref, adj); 963 } 964 if (UVM_ET_ISSUBMAP(entry1)) { 965 /* ... unlikely to happen, but play it safe */ 966 uvm_map_reference(entry1->object.sub_map); 967 } else if (UVM_ET_ISOBJ(entry1)) { 968 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 969 entry2->offset += adj; 970 if (entry1->object.uvm_obj->pgops && 971 entry1->object.uvm_obj->pgops->pgo_reference) 972 entry1->object.uvm_obj->pgops->pgo_reference( 973 entry1->object.uvm_obj); 974 } 975 } 976 977 /* 978 * uvm_map_clip_start: ensure that the entry begins at or after 979 * the starting address, if it doesn't we split the entry. 980 * 981 * => caller should use UVM_MAP_CLIP_START macro rather than calling 982 * this directly 983 * => map must be locked by caller 984 */ 985 986 void 987 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 988 vaddr_t start) 989 { 990 struct vm_map_entry *new_entry; 991 992 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 993 994 uvm_map_check(map, "clip_start entry"); 995 uvm_mapent_check(entry); 996 997 /* 998 * Split off the front portion. note that we must insert the new 999 * entry BEFORE this one, so that this entry has the specified 1000 * starting address. 1001 */ 1002 new_entry = uvm_mapent_alloc(map, 0); 1003 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1004 uvm_mapent_splitadj(new_entry, entry, start); 1005 uvm_map_entry_link(map, entry->prev, new_entry); 1006 1007 uvm_map_check(map, "clip_start leave"); 1008 } 1009 1010 /* 1011 * uvm_map_clip_end: ensure that the entry ends at or before 1012 * the ending address, if it does't we split the reference 1013 * 1014 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1015 * this directly 1016 * => map must be locked by caller 1017 */ 1018 1019 void 1020 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end) 1021 { 1022 struct vm_map_entry *new_entry; 1023 1024 uvm_map_check(map, "clip_end entry"); 1025 uvm_mapent_check(entry); 1026 1027 /* 1028 * Create a new entry and insert it 1029 * AFTER the specified entry 1030 */ 1031 new_entry = uvm_mapent_alloc(map, 0); 1032 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1033 uvm_mapent_splitadj(entry, new_entry, end); 1034 uvm_map_entry_link(map, entry, new_entry); 1035 1036 uvm_map_check(map, "clip_end leave"); 1037 } 1038 1039 /* 1040 * M A P - m a i n e n t r y p o i n t 1041 */ 1042 /* 1043 * uvm_map: establish a valid mapping in a map 1044 * 1045 * => assume startp is page aligned. 1046 * => assume size is a multiple of PAGE_SIZE. 1047 * => assume sys_mmap provides enough of a "hint" to have us skip 1048 * over text/data/bss area. 1049 * => map must be unlocked (we will lock it) 1050 * => <uobj,uoffset> value meanings (4 cases): 1051 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1052 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1053 * [3] <uobj,uoffset> == normal mapping 1054 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1055 * 1056 * case [4] is for kernel mappings where we don't know the offset until 1057 * we've found a virtual address. note that kernel object offsets are 1058 * always relative to vm_map_min(kernel_map). 1059 * 1060 * => if `align' is non-zero, we align the virtual address to the specified 1061 * alignment. 1062 * this is provided as a mechanism for large pages. 1063 * 1064 * => XXXCDC: need way to map in external amap? 1065 */ 1066 1067 int 1068 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1069 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1070 { 1071 struct uvm_map_args args; 1072 struct vm_map_entry *new_entry; 1073 int error; 1074 1075 KASSERT((size & PAGE_MASK) == 0); 1076 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1077 1078 /* 1079 * for pager_map, allocate the new entry first to avoid sleeping 1080 * for memory while we have the map locked. 1081 */ 1082 1083 new_entry = NULL; 1084 if (map == pager_map) { 1085 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1086 if (__predict_false(new_entry == NULL)) 1087 return ENOMEM; 1088 } 1089 if (map == pager_map) 1090 flags |= UVM_FLAG_NOMERGE; 1091 1092 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1093 flags, &args); 1094 if (!error) { 1095 error = uvm_map_enter(map, &args, new_entry); 1096 *startp = args.uma_start; 1097 } else if (new_entry) { 1098 uvm_mapent_free(new_entry); 1099 } 1100 1101 #if defined(DEBUG) 1102 if (!error && VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 1103 uvm_km_check_empty(map, *startp, *startp + size); 1104 } 1105 #endif /* defined(DEBUG) */ 1106 1107 return error; 1108 } 1109 1110 /* 1111 * uvm_map_prepare: 1112 * 1113 * called with map unlocked. 1114 * on success, returns the map locked. 1115 */ 1116 1117 int 1118 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1119 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1120 struct uvm_map_args *args) 1121 { 1122 struct vm_map_entry *prev_entry; 1123 vm_prot_t prot = UVM_PROTECTION(flags); 1124 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1125 1126 UVMHIST_FUNC(__func__); 1127 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1128 (uintptr_t)map, start, size, flags); 1129 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1130 uoffset,0,0); 1131 1132 /* 1133 * detect a popular device driver bug. 1134 */ 1135 1136 KASSERT(doing_shutdown || curlwp != NULL); 1137 1138 /* 1139 * zero-sized mapping doesn't make any sense. 1140 */ 1141 KASSERT(size > 0); 1142 1143 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1144 1145 uvm_map_check(map, "map entry"); 1146 1147 /* 1148 * check sanity of protection code 1149 */ 1150 1151 if ((prot & maxprot) != prot) { 1152 UVMHIST_LOG(maphist, "<- prot. failure: prot=%#jx, max=%#jx", 1153 prot, maxprot,0,0); 1154 return EACCES; 1155 } 1156 1157 /* 1158 * figure out where to put new VM range 1159 */ 1160 retry: 1161 if (vm_map_lock_try(map) == false) { 1162 if ((flags & UVM_FLAG_TRYLOCK) != 0) { 1163 return EAGAIN; 1164 } 1165 vm_map_lock(map); /* could sleep here */ 1166 } 1167 if (flags & UVM_FLAG_UNMAP) { 1168 KASSERT(flags & UVM_FLAG_FIXED); 1169 KASSERT((flags & UVM_FLAG_NOWAIT) == 0); 1170 1171 /* 1172 * Set prev_entry to what it will need to be after any existing 1173 * entries are removed later in uvm_map_enter(). 1174 */ 1175 1176 if (uvm_map_lookup_entry(map, start, &prev_entry)) { 1177 if (start == prev_entry->start) 1178 prev_entry = prev_entry->prev; 1179 else 1180 UVM_MAP_CLIP_END(map, prev_entry, start); 1181 SAVE_HINT(map, map->hint, prev_entry); 1182 } 1183 } else { 1184 prev_entry = uvm_map_findspace(map, start, size, &start, 1185 uobj, uoffset, align, flags); 1186 } 1187 if (prev_entry == NULL) { 1188 unsigned int timestamp; 1189 1190 timestamp = map->timestamp; 1191 UVMHIST_LOG(maphist,"waiting va timestamp=%#jx", 1192 timestamp,0,0,0); 1193 map->flags |= VM_MAP_WANTVA; 1194 vm_map_unlock(map); 1195 1196 /* 1197 * try to reclaim kva and wait until someone does unmap. 1198 * fragile locking here, so we awaken every second to 1199 * recheck the condition. 1200 */ 1201 1202 mutex_enter(&map->misc_lock); 1203 while ((map->flags & VM_MAP_WANTVA) != 0 && 1204 map->timestamp == timestamp) { 1205 if ((flags & UVM_FLAG_WAITVA) == 0) { 1206 mutex_exit(&map->misc_lock); 1207 UVMHIST_LOG(maphist, 1208 "<- uvm_map_findspace failed!", 0,0,0,0); 1209 return ENOMEM; 1210 } else { 1211 cv_timedwait(&map->cv, &map->misc_lock, hz); 1212 } 1213 } 1214 mutex_exit(&map->misc_lock); 1215 goto retry; 1216 } 1217 1218 #ifdef PMAP_GROWKERNEL 1219 /* 1220 * If the kernel pmap can't map the requested space, 1221 * then allocate more resources for it. 1222 */ 1223 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1224 uvm_maxkaddr = pmap_growkernel(start + size); 1225 #endif 1226 1227 UVMMAP_EVCNT_INCR(map_call); 1228 1229 /* 1230 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1231 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1232 * either case we want to zero it before storing it in the map entry 1233 * (because it looks strange and confusing when debugging...) 1234 * 1235 * if uobj is not null 1236 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1237 * and we do not need to change uoffset. 1238 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1239 * now (based on the starting address of the map). this case is 1240 * for kernel object mappings where we don't know the offset until 1241 * the virtual address is found (with uvm_map_findspace). the 1242 * offset is the distance we are from the start of the map. 1243 */ 1244 1245 if (uobj == NULL) { 1246 uoffset = 0; 1247 } else { 1248 if (uoffset == UVM_UNKNOWN_OFFSET) { 1249 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1250 uoffset = start - vm_map_min(kernel_map); 1251 } 1252 } 1253 1254 args->uma_flags = flags; 1255 args->uma_prev = prev_entry; 1256 args->uma_start = start; 1257 args->uma_size = size; 1258 args->uma_uobj = uobj; 1259 args->uma_uoffset = uoffset; 1260 1261 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1262 return 0; 1263 } 1264 1265 /* 1266 * uvm_map_enter: 1267 * 1268 * called with map locked. 1269 * unlock the map before returning. 1270 */ 1271 1272 int 1273 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1274 struct vm_map_entry *new_entry) 1275 { 1276 struct vm_map_entry *prev_entry = args->uma_prev; 1277 struct vm_map_entry *dead = NULL, *dead_entries = NULL; 1278 1279 const uvm_flag_t flags = args->uma_flags; 1280 const vm_prot_t prot = UVM_PROTECTION(flags); 1281 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1282 const vm_inherit_t inherit = UVM_INHERIT(flags); 1283 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1284 AMAP_EXTEND_NOWAIT : 0; 1285 const int advice = UVM_ADVICE(flags); 1286 1287 vaddr_t start = args->uma_start; 1288 vsize_t size = args->uma_size; 1289 struct uvm_object *uobj = args->uma_uobj; 1290 voff_t uoffset = args->uma_uoffset; 1291 1292 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1293 int merged = 0; 1294 int error; 1295 int newetype; 1296 1297 UVMHIST_FUNC(__func__); 1298 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)", 1299 (uintptr_t)map, start, size, flags); 1300 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj, 1301 uoffset,0,0); 1302 1303 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1304 KASSERT(vm_map_locked_p(map)); 1305 KASSERT((flags & (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)) != 1306 (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)); 1307 1308 if (uobj) 1309 newetype = UVM_ET_OBJ; 1310 else 1311 newetype = 0; 1312 1313 if (flags & UVM_FLAG_COPYONW) { 1314 newetype |= UVM_ET_COPYONWRITE; 1315 if ((flags & UVM_FLAG_OVERLAY) == 0) 1316 newetype |= UVM_ET_NEEDSCOPY; 1317 } 1318 1319 /* 1320 * For mappings with unmap, remove any old entries now. Adding the new 1321 * entry cannot fail because that can only happen if UVM_FLAG_NOWAIT 1322 * is set, and we do not support nowait and unmap together. 1323 */ 1324 1325 if (flags & UVM_FLAG_UNMAP) { 1326 KASSERT(flags & UVM_FLAG_FIXED); 1327 uvm_unmap_remove(map, start, start + size, &dead_entries, 0); 1328 #ifdef DEBUG 1329 struct vm_map_entry *tmp_entry __diagused; 1330 bool rv __diagused; 1331 1332 rv = uvm_map_lookup_entry(map, start, &tmp_entry); 1333 KASSERT(!rv); 1334 KASSERTMSG(prev_entry == tmp_entry, 1335 "args %p prev_entry %p tmp_entry %p", 1336 args, prev_entry, tmp_entry); 1337 #endif 1338 SAVE_HINT(map, map->hint, prev_entry); 1339 } 1340 1341 /* 1342 * try and insert in map by extending previous entry, if possible. 1343 * XXX: we don't try and pull back the next entry. might be useful 1344 * for a stack, but we are currently allocating our stack in advance. 1345 */ 1346 1347 if (flags & UVM_FLAG_NOMERGE) 1348 goto nomerge; 1349 1350 if (prev_entry->end == start && 1351 prev_entry != &map->header && 1352 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, 0, 1353 prot, maxprot, inherit, advice, 0)) { 1354 1355 if (uobj && prev_entry->offset + 1356 (prev_entry->end - prev_entry->start) != uoffset) 1357 goto forwardmerge; 1358 1359 /* 1360 * can't extend a shared amap. note: no need to lock amap to 1361 * look at refs since we don't care about its exact value. 1362 * if it is one (i.e. we have only reference) it will stay there 1363 */ 1364 1365 if (prev_entry->aref.ar_amap && 1366 amap_refs(prev_entry->aref.ar_amap) != 1) { 1367 goto forwardmerge; 1368 } 1369 1370 if (prev_entry->aref.ar_amap) { 1371 error = amap_extend(prev_entry, size, 1372 amapwaitflag | AMAP_EXTEND_FORWARDS); 1373 if (error) 1374 goto nomerge; 1375 } 1376 1377 if (kmap) { 1378 UVMMAP_EVCNT_INCR(kbackmerge); 1379 } else { 1380 UVMMAP_EVCNT_INCR(ubackmerge); 1381 } 1382 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1383 1384 /* 1385 * drop our reference to uobj since we are extending a reference 1386 * that we already have (the ref count can not drop to zero). 1387 */ 1388 1389 if (uobj && uobj->pgops->pgo_detach) 1390 uobj->pgops->pgo_detach(uobj); 1391 1392 /* 1393 * Now that we've merged the entries, note that we've grown 1394 * and our gap has shrunk. Then fix the tree. 1395 */ 1396 prev_entry->end += size; 1397 prev_entry->gap -= size; 1398 uvm_rb_fixup(map, prev_entry); 1399 1400 uvm_map_check(map, "map backmerged"); 1401 1402 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1403 merged++; 1404 } 1405 1406 forwardmerge: 1407 if (prev_entry->next->start == (start + size) && 1408 prev_entry->next != &map->header && 1409 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, 0, 1410 prot, maxprot, inherit, advice, 0)) { 1411 1412 if (uobj && prev_entry->next->offset != uoffset + size) 1413 goto nomerge; 1414 1415 /* 1416 * can't extend a shared amap. note: no need to lock amap to 1417 * look at refs since we don't care about its exact value. 1418 * if it is one (i.e. we have only reference) it will stay there. 1419 * 1420 * note that we also can't merge two amaps, so if we 1421 * merged with the previous entry which has an amap, 1422 * and the next entry also has an amap, we give up. 1423 * 1424 * Interesting cases: 1425 * amap, new, amap -> give up second merge (single fwd extend) 1426 * amap, new, none -> double forward extend (extend again here) 1427 * none, new, amap -> double backward extend (done here) 1428 * uobj, new, amap -> single backward extend (done here) 1429 * 1430 * XXX should we attempt to deal with someone refilling 1431 * the deallocated region between two entries that are 1432 * backed by the same amap (ie, arefs is 2, "prev" and 1433 * "next" refer to it, and adding this allocation will 1434 * close the hole, thus restoring arefs to 1 and 1435 * deallocating the "next" vm_map_entry)? -- @@@ 1436 */ 1437 1438 if (prev_entry->next->aref.ar_amap && 1439 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1440 (merged && prev_entry->aref.ar_amap))) { 1441 goto nomerge; 1442 } 1443 1444 if (merged) { 1445 /* 1446 * Try to extend the amap of the previous entry to 1447 * cover the next entry as well. If it doesn't work 1448 * just skip on, don't actually give up, since we've 1449 * already completed the back merge. 1450 */ 1451 if (prev_entry->aref.ar_amap) { 1452 if (amap_extend(prev_entry, 1453 prev_entry->next->end - 1454 prev_entry->next->start, 1455 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1456 goto nomerge; 1457 } 1458 1459 /* 1460 * Try to extend the amap of the *next* entry 1461 * back to cover the new allocation *and* the 1462 * previous entry as well (the previous merge 1463 * didn't have an amap already otherwise we 1464 * wouldn't be checking here for an amap). If 1465 * it doesn't work just skip on, again, don't 1466 * actually give up, since we've already 1467 * completed the back merge. 1468 */ 1469 else if (prev_entry->next->aref.ar_amap) { 1470 if (amap_extend(prev_entry->next, 1471 prev_entry->end - 1472 prev_entry->start, 1473 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1474 goto nomerge; 1475 } 1476 } else { 1477 /* 1478 * Pull the next entry's amap backwards to cover this 1479 * new allocation. 1480 */ 1481 if (prev_entry->next->aref.ar_amap) { 1482 error = amap_extend(prev_entry->next, size, 1483 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1484 if (error) 1485 goto nomerge; 1486 } 1487 } 1488 1489 if (merged) { 1490 if (kmap) { 1491 UVMMAP_EVCNT_DECR(kbackmerge); 1492 UVMMAP_EVCNT_INCR(kbimerge); 1493 } else { 1494 UVMMAP_EVCNT_DECR(ubackmerge); 1495 UVMMAP_EVCNT_INCR(ubimerge); 1496 } 1497 } else { 1498 if (kmap) { 1499 UVMMAP_EVCNT_INCR(kforwmerge); 1500 } else { 1501 UVMMAP_EVCNT_INCR(uforwmerge); 1502 } 1503 } 1504 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1505 1506 /* 1507 * drop our reference to uobj since we are extending a reference 1508 * that we already have (the ref count can not drop to zero). 1509 */ 1510 if (uobj && uobj->pgops->pgo_detach) 1511 uobj->pgops->pgo_detach(uobj); 1512 1513 if (merged) { 1514 dead = prev_entry->next; 1515 prev_entry->end = dead->end; 1516 uvm_map_entry_unlink(map, dead); 1517 if (dead->aref.ar_amap != NULL) { 1518 prev_entry->aref = dead->aref; 1519 dead->aref.ar_amap = NULL; 1520 } 1521 } else { 1522 prev_entry->next->start -= size; 1523 if (prev_entry != &map->header) { 1524 prev_entry->gap -= size; 1525 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1526 uvm_rb_fixup(map, prev_entry); 1527 } 1528 if (uobj) 1529 prev_entry->next->offset = uoffset; 1530 } 1531 1532 uvm_map_check(map, "map forwardmerged"); 1533 1534 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1535 merged++; 1536 } 1537 1538 nomerge: 1539 if (!merged) { 1540 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1541 if (kmap) { 1542 UVMMAP_EVCNT_INCR(knomerge); 1543 } else { 1544 UVMMAP_EVCNT_INCR(unomerge); 1545 } 1546 1547 /* 1548 * allocate new entry and link it in. 1549 */ 1550 1551 if (new_entry == NULL) { 1552 new_entry = uvm_mapent_alloc(map, 1553 (flags & UVM_FLAG_NOWAIT)); 1554 if (__predict_false(new_entry == NULL)) { 1555 error = ENOMEM; 1556 goto done; 1557 } 1558 } 1559 new_entry->start = start; 1560 new_entry->end = new_entry->start + size; 1561 new_entry->object.uvm_obj = uobj; 1562 new_entry->offset = uoffset; 1563 1564 new_entry->etype = newetype; 1565 1566 if (flags & UVM_FLAG_NOMERGE) { 1567 new_entry->flags |= UVM_MAP_NOMERGE; 1568 } 1569 1570 new_entry->protection = prot; 1571 new_entry->max_protection = maxprot; 1572 new_entry->inheritance = inherit; 1573 new_entry->wired_count = 0; 1574 new_entry->advice = advice; 1575 if (flags & UVM_FLAG_OVERLAY) { 1576 1577 /* 1578 * to_add: for BSS we overallocate a little since we 1579 * are likely to extend 1580 */ 1581 1582 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1583 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1584 struct vm_amap *amap = amap_alloc(size, to_add, 1585 (flags & UVM_FLAG_NOWAIT)); 1586 if (__predict_false(amap == NULL)) { 1587 error = ENOMEM; 1588 goto done; 1589 } 1590 new_entry->aref.ar_pageoff = 0; 1591 new_entry->aref.ar_amap = amap; 1592 } else { 1593 new_entry->aref.ar_pageoff = 0; 1594 new_entry->aref.ar_amap = NULL; 1595 } 1596 uvm_map_entry_link(map, prev_entry, new_entry); 1597 1598 /* 1599 * Update the free space hint 1600 */ 1601 1602 if ((map->first_free == prev_entry) && 1603 (prev_entry->end >= new_entry->start)) 1604 map->first_free = new_entry; 1605 1606 new_entry = NULL; 1607 } 1608 1609 map->size += size; 1610 1611 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1612 1613 error = 0; 1614 1615 done: 1616 vm_map_unlock(map); 1617 1618 if (new_entry) { 1619 uvm_mapent_free(new_entry); 1620 } 1621 if (dead) { 1622 KDASSERT(merged); 1623 uvm_mapent_free(dead); 1624 } 1625 if (dead_entries) 1626 uvm_unmap_detach(dead_entries, 0); 1627 1628 return error; 1629 } 1630 1631 /* 1632 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1633 */ 1634 1635 static inline bool 1636 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1637 struct vm_map_entry **entry /* OUT */) 1638 { 1639 struct vm_map_entry *prev = &map->header; 1640 struct vm_map_entry *cur = ROOT_ENTRY(map); 1641 1642 while (cur) { 1643 UVMMAP_EVCNT_INCR(mlk_treeloop); 1644 if (address >= cur->start) { 1645 if (address < cur->end) { 1646 *entry = cur; 1647 return true; 1648 } 1649 prev = cur; 1650 cur = RIGHT_ENTRY(cur); 1651 } else 1652 cur = LEFT_ENTRY(cur); 1653 } 1654 *entry = prev; 1655 return false; 1656 } 1657 1658 /* 1659 * uvm_map_lookup_entry: find map entry at or before an address 1660 * 1661 * => map must at least be read-locked by caller 1662 * => entry is returned in "entry" 1663 * => return value is true if address is in the returned entry 1664 */ 1665 1666 bool 1667 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1668 struct vm_map_entry **entry /* OUT */) 1669 { 1670 struct vm_map_entry *cur; 1671 UVMHIST_FUNC(__func__); 1672 UVMHIST_CALLARGS(maphist,"(map=%#jx,addr=%#jx,ent=%#jx)", 1673 (uintptr_t)map, address, (uintptr_t)entry, 0); 1674 1675 /* 1676 * make a quick check to see if we are already looking at 1677 * the entry we want (which is usually the case). note also 1678 * that we don't need to save the hint here... it is the 1679 * same hint (unless we are at the header, in which case the 1680 * hint didn't buy us anything anyway). 1681 */ 1682 1683 cur = map->hint; 1684 UVMMAP_EVCNT_INCR(mlk_call); 1685 if (cur != &map->header && 1686 address >= cur->start && cur->end > address) { 1687 UVMMAP_EVCNT_INCR(mlk_hint); 1688 *entry = cur; 1689 UVMHIST_LOG(maphist,"<- got it via hint (%#jx)", 1690 (uintptr_t)cur, 0, 0, 0); 1691 uvm_mapent_check(*entry); 1692 return (true); 1693 } 1694 uvm_map_check(map, __func__); 1695 1696 /* 1697 * lookup in the tree. 1698 */ 1699 1700 UVMMAP_EVCNT_INCR(mlk_tree); 1701 if (__predict_true(uvm_map_lookup_entry_bytree(map, address, entry))) { 1702 SAVE_HINT(map, map->hint, *entry); 1703 UVMHIST_LOG(maphist,"<- search got it (%#jx)", 1704 (uintptr_t)cur, 0, 0, 0); 1705 KDASSERT((*entry)->start <= address); 1706 KDASSERT(address < (*entry)->end); 1707 uvm_mapent_check(*entry); 1708 return (true); 1709 } 1710 1711 SAVE_HINT(map, map->hint, *entry); 1712 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1713 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1714 KDASSERT((*entry)->next == &map->header || 1715 address < (*entry)->next->start); 1716 return (false); 1717 } 1718 1719 /* 1720 * See if the range between start and start + length fits in the gap 1721 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1722 * fit, and -1 address wraps around. 1723 */ 1724 static int 1725 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1726 vsize_t align, int flags, int topdown, struct vm_map_entry *entry) 1727 { 1728 vaddr_t end; 1729 1730 #ifdef PMAP_PREFER 1731 /* 1732 * push start address forward as needed to avoid VAC alias problems. 1733 * we only do this if a valid offset is specified. 1734 */ 1735 1736 if (uoffset != UVM_UNKNOWN_OFFSET) 1737 PMAP_PREFER(uoffset, start, length, topdown); 1738 #endif 1739 if ((flags & UVM_FLAG_COLORMATCH) != 0) { 1740 KASSERT(align < uvmexp.ncolors); 1741 if (uvmexp.ncolors > 1) { 1742 const u_int colormask = uvmexp.colormask; 1743 const u_int colorsize = colormask + 1; 1744 vaddr_t hint = atop(*start); 1745 const u_int color = hint & colormask; 1746 if (color != align) { 1747 hint -= color; /* adjust to color boundary */ 1748 KASSERT((hint & colormask) == 0); 1749 if (topdown) { 1750 if (align > color) 1751 hint -= colorsize; 1752 } else { 1753 if (align < color) 1754 hint += colorsize; 1755 } 1756 *start = ptoa(hint + align); /* adjust to color */ 1757 } 1758 } 1759 } else { 1760 KASSERT(powerof2(align)); 1761 uvm_map_align_va(start, align, topdown); 1762 /* 1763 * XXX Should we PMAP_PREFER() here again? 1764 * eh...i think we're okay 1765 */ 1766 } 1767 1768 /* 1769 * Find the end of the proposed new region. Be sure we didn't 1770 * wrap around the address; if so, we lose. Otherwise, if the 1771 * proposed new region fits before the next entry, we win. 1772 */ 1773 1774 end = *start + length; 1775 if (end < *start) 1776 return (-1); 1777 1778 if (entry->next->start >= end && *start >= entry->end) 1779 return (1); 1780 1781 return (0); 1782 } 1783 1784 /* 1785 * uvm_map_findspace: find "length" sized space in "map". 1786 * 1787 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1788 * set in "flags" (in which case we insist on using "hint"). 1789 * => "result" is VA returned 1790 * => uobj/uoffset are to be used to handle VAC alignment, if required 1791 * => if "align" is non-zero, we attempt to align to that value. 1792 * => caller must at least have read-locked map 1793 * => returns NULL on failure, or pointer to prev. map entry if success 1794 * => note this is a cross between the old vm_map_findspace and vm_map_find 1795 */ 1796 1797 struct vm_map_entry * 1798 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1799 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1800 vsize_t align, int flags) 1801 { 1802 struct vm_map_entry *entry; 1803 struct vm_map_entry *child, *prev, *tmp; 1804 vaddr_t orig_hint __diagused; 1805 const int topdown = map->flags & VM_MAP_TOPDOWN; 1806 UVMHIST_FUNC(__func__); 1807 UVMHIST_CALLARGS(maphist, "(map=%#jx, hint=%#jx, len=%ju, flags=%#jx)", 1808 (uintptr_t)map, hint, length, flags); 1809 1810 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || powerof2(align)); 1811 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors); 1812 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1813 1814 uvm_map_check(map, "map_findspace entry"); 1815 1816 /* 1817 * remember the original hint. if we are aligning, then we 1818 * may have to try again with no alignment constraint if 1819 * we fail the first time. 1820 */ 1821 1822 orig_hint = hint; 1823 if (hint < vm_map_min(map)) { /* check ranges ... */ 1824 if (flags & UVM_FLAG_FIXED) { 1825 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1826 return (NULL); 1827 } 1828 hint = vm_map_min(map); 1829 } 1830 if (hint > vm_map_max(map)) { 1831 UVMHIST_LOG(maphist,"<- VA %#jx > range [%#jx->%#jx]", 1832 hint, vm_map_min(map), vm_map_max(map), 0); 1833 return (NULL); 1834 } 1835 1836 /* 1837 * hint may not be aligned properly; we need round up or down it 1838 * before proceeding further. 1839 */ 1840 if ((flags & UVM_FLAG_COLORMATCH) == 0) 1841 uvm_map_align_va(&hint, align, topdown); 1842 1843 /* 1844 * Look for the first possible address; if there's already 1845 * something at this address, we have to start after it. 1846 */ 1847 1848 /* 1849 * @@@: there are four, no, eight cases to consider. 1850 * 1851 * 0: found, fixed, bottom up -> fail 1852 * 1: found, fixed, top down -> fail 1853 * 2: found, not fixed, bottom up -> start after entry->end, 1854 * loop up 1855 * 3: found, not fixed, top down -> start before entry->start, 1856 * loop down 1857 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1858 * 5: not found, fixed, top down -> check entry->next->start, fail 1859 * 6: not found, not fixed, bottom up -> check entry->next->start, 1860 * loop up 1861 * 7: not found, not fixed, top down -> check entry->next->start, 1862 * loop down 1863 * 1864 * as you can see, it reduces to roughly five cases, and that 1865 * adding top down mapping only adds one unique case (without 1866 * it, there would be four cases). 1867 */ 1868 1869 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1870 entry = map->first_free; 1871 } else { 1872 if (uvm_map_lookup_entry(map, hint, &entry)) { 1873 /* "hint" address already in use ... */ 1874 if (flags & UVM_FLAG_FIXED) { 1875 UVMHIST_LOG(maphist, "<- fixed & VA in use", 1876 0, 0, 0, 0); 1877 return (NULL); 1878 } 1879 if (topdown) 1880 /* Start from lower gap. */ 1881 entry = entry->prev; 1882 } else if (flags & UVM_FLAG_FIXED) { 1883 if (entry->next->start >= hint + length && 1884 hint + length > hint) 1885 goto found; 1886 1887 /* "hint" address is gap but too small */ 1888 UVMHIST_LOG(maphist, "<- fixed mapping failed", 1889 0, 0, 0, 0); 1890 return (NULL); /* only one shot at it ... */ 1891 } else { 1892 /* 1893 * See if given hint fits in this gap. 1894 */ 1895 switch (uvm_map_space_avail(&hint, length, 1896 uoffset, align, flags, topdown, entry)) { 1897 case 1: 1898 goto found; 1899 case -1: 1900 goto wraparound; 1901 } 1902 1903 if (topdown) { 1904 /* 1905 * Still there is a chance to fit 1906 * if hint > entry->end. 1907 */ 1908 } else { 1909 /* Start from higher gap. */ 1910 entry = entry->next; 1911 if (entry == &map->header) 1912 goto notfound; 1913 goto nextgap; 1914 } 1915 } 1916 } 1917 1918 /* 1919 * Note that all UVM_FLAGS_FIXED case is already handled. 1920 */ 1921 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1922 1923 /* Try to find the space in the red-black tree */ 1924 1925 /* Check slot before any entry */ 1926 hint = topdown ? entry->next->start - length : entry->end; 1927 switch (uvm_map_space_avail(&hint, length, uoffset, align, flags, 1928 topdown, entry)) { 1929 case 1: 1930 goto found; 1931 case -1: 1932 goto wraparound; 1933 } 1934 1935 nextgap: 1936 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 1937 /* If there is not enough space in the whole tree, we fail */ 1938 tmp = ROOT_ENTRY(map); 1939 if (tmp == NULL || tmp->maxgap < length) 1940 goto notfound; 1941 1942 prev = NULL; /* previous candidate */ 1943 1944 /* Find an entry close to hint that has enough space */ 1945 for (; tmp;) { 1946 KASSERT(tmp->next->start == tmp->end + tmp->gap); 1947 if (topdown) { 1948 if (tmp->next->start < hint + length && 1949 (prev == NULL || tmp->end > prev->end)) { 1950 if (tmp->gap >= length) 1951 prev = tmp; 1952 else if ((child = LEFT_ENTRY(tmp)) != NULL 1953 && child->maxgap >= length) 1954 prev = tmp; 1955 } 1956 } else { 1957 if (tmp->end >= hint && 1958 (prev == NULL || tmp->end < prev->end)) { 1959 if (tmp->gap >= length) 1960 prev = tmp; 1961 else if ((child = RIGHT_ENTRY(tmp)) != NULL 1962 && child->maxgap >= length) 1963 prev = tmp; 1964 } 1965 } 1966 if (tmp->next->start < hint + length) 1967 child = RIGHT_ENTRY(tmp); 1968 else if (tmp->end > hint) 1969 child = LEFT_ENTRY(tmp); 1970 else { 1971 if (tmp->gap >= length) 1972 break; 1973 if (topdown) 1974 child = LEFT_ENTRY(tmp); 1975 else 1976 child = RIGHT_ENTRY(tmp); 1977 } 1978 if (child == NULL || child->maxgap < length) 1979 break; 1980 tmp = child; 1981 } 1982 1983 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 1984 /* 1985 * Check if the entry that we found satifies the 1986 * space requirement 1987 */ 1988 if (topdown) { 1989 if (hint > tmp->next->start - length) 1990 hint = tmp->next->start - length; 1991 } else { 1992 if (hint < tmp->end) 1993 hint = tmp->end; 1994 } 1995 switch (uvm_map_space_avail(&hint, length, uoffset, align, 1996 flags, topdown, tmp)) { 1997 case 1: 1998 entry = tmp; 1999 goto found; 2000 case -1: 2001 goto wraparound; 2002 } 2003 if (tmp->gap >= length) 2004 goto listsearch; 2005 } 2006 if (prev == NULL) 2007 goto notfound; 2008 2009 if (topdown) { 2010 KASSERT(orig_hint >= prev->next->start - length || 2011 prev->next->start - length > prev->next->start); 2012 hint = prev->next->start - length; 2013 } else { 2014 KASSERT(orig_hint <= prev->end); 2015 hint = prev->end; 2016 } 2017 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2018 flags, topdown, prev)) { 2019 case 1: 2020 entry = prev; 2021 goto found; 2022 case -1: 2023 goto wraparound; 2024 } 2025 if (prev->gap >= length) 2026 goto listsearch; 2027 2028 if (topdown) 2029 tmp = LEFT_ENTRY(prev); 2030 else 2031 tmp = RIGHT_ENTRY(prev); 2032 for (;;) { 2033 KASSERT(tmp && tmp->maxgap >= length); 2034 if (topdown) 2035 child = RIGHT_ENTRY(tmp); 2036 else 2037 child = LEFT_ENTRY(tmp); 2038 if (child && child->maxgap >= length) { 2039 tmp = child; 2040 continue; 2041 } 2042 if (tmp->gap >= length) 2043 break; 2044 if (topdown) 2045 tmp = LEFT_ENTRY(tmp); 2046 else 2047 tmp = RIGHT_ENTRY(tmp); 2048 } 2049 2050 if (topdown) { 2051 KASSERT(orig_hint >= tmp->next->start - length || 2052 tmp->next->start - length > tmp->next->start); 2053 hint = tmp->next->start - length; 2054 } else { 2055 KASSERT(orig_hint <= tmp->end); 2056 hint = tmp->end; 2057 } 2058 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2059 flags, topdown, tmp)) { 2060 case 1: 2061 entry = tmp; 2062 goto found; 2063 case -1: 2064 goto wraparound; 2065 } 2066 2067 /* 2068 * The tree fails to find an entry because of offset or alignment 2069 * restrictions. Search the list instead. 2070 */ 2071 listsearch: 2072 /* 2073 * Look through the rest of the map, trying to fit a new region in 2074 * the gap between existing regions, or after the very last region. 2075 * note: entry->end = base VA of current gap, 2076 * entry->next->start = VA of end of current gap 2077 */ 2078 2079 for (;;) { 2080 /* Update hint for current gap. */ 2081 hint = topdown ? entry->next->start - length : entry->end; 2082 2083 /* See if it fits. */ 2084 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2085 flags, topdown, entry)) { 2086 case 1: 2087 goto found; 2088 case -1: 2089 goto wraparound; 2090 } 2091 2092 /* Advance to next/previous gap */ 2093 if (topdown) { 2094 if (entry == &map->header) { 2095 UVMHIST_LOG(maphist, "<- failed (off start)", 2096 0,0,0,0); 2097 goto notfound; 2098 } 2099 entry = entry->prev; 2100 } else { 2101 entry = entry->next; 2102 if (entry == &map->header) { 2103 UVMHIST_LOG(maphist, "<- failed (off end)", 2104 0,0,0,0); 2105 goto notfound; 2106 } 2107 } 2108 } 2109 2110 found: 2111 SAVE_HINT(map, map->hint, entry); 2112 *result = hint; 2113 UVMHIST_LOG(maphist,"<- got it! (result=%#jx)", hint, 0,0,0); 2114 KASSERTMSG( topdown || hint >= orig_hint, "hint: %#jx, orig_hint: %#jx", 2115 (uintmax_t)hint, (uintmax_t)orig_hint); 2116 KASSERTMSG(!topdown || hint <= orig_hint, "hint: %#jx, orig_hint: %#jx", 2117 (uintmax_t)hint, (uintmax_t)orig_hint); 2118 KASSERT(entry->end <= hint); 2119 KASSERT(hint + length <= entry->next->start); 2120 return (entry); 2121 2122 wraparound: 2123 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2124 2125 return (NULL); 2126 2127 notfound: 2128 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2129 2130 return (NULL); 2131 } 2132 2133 /* 2134 * U N M A P - m a i n h e l p e r f u n c t i o n s 2135 */ 2136 2137 /* 2138 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2139 * 2140 * => caller must check alignment and size 2141 * => map must be locked by caller 2142 * => we return a list of map entries that we've remove from the map 2143 * in "entry_list" 2144 */ 2145 2146 void 2147 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2148 struct vm_map_entry **entry_list /* OUT */, int flags) 2149 { 2150 struct vm_map_entry *entry, *first_entry, *next; 2151 vaddr_t len; 2152 UVMHIST_FUNC(__func__); 2153 UVMHIST_CALLARGS(maphist,"(map=%#jx, start=%#jx, end=%#jx)", 2154 (uintptr_t)map, start, end, 0); 2155 VM_MAP_RANGE_CHECK(map, start, end); 2156 2157 uvm_map_check(map, "unmap_remove entry"); 2158 2159 /* 2160 * find first entry 2161 */ 2162 2163 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2164 /* clip and go... */ 2165 entry = first_entry; 2166 UVM_MAP_CLIP_START(map, entry, start); 2167 /* critical! prevents stale hint */ 2168 SAVE_HINT(map, entry, entry->prev); 2169 } else { 2170 entry = first_entry->next; 2171 } 2172 2173 /* 2174 * save the free space hint 2175 */ 2176 2177 if (map->first_free != &map->header && map->first_free->start >= start) 2178 map->first_free = entry->prev; 2179 2180 /* 2181 * note: we now re-use first_entry for a different task. we remove 2182 * a number of map entries from the map and save them in a linked 2183 * list headed by "first_entry". once we remove them from the map 2184 * the caller should unlock the map and drop the references to the 2185 * backing objects [c.f. uvm_unmap_detach]. the object is to 2186 * separate unmapping from reference dropping. why? 2187 * [1] the map has to be locked for unmapping 2188 * [2] the map need not be locked for reference dropping 2189 * [3] dropping references may trigger pager I/O, and if we hit 2190 * a pager that does synchronous I/O we may have to wait for it. 2191 * [4] we would like all waiting for I/O to occur with maps unlocked 2192 * so that we don't block other threads. 2193 */ 2194 2195 first_entry = NULL; 2196 *entry_list = NULL; 2197 2198 /* 2199 * break up the area into map entry sized regions and unmap. note 2200 * that all mappings have to be removed before we can even consider 2201 * dropping references to amaps or VM objects (otherwise we could end 2202 * up with a mapping to a page on the free list which would be very bad) 2203 */ 2204 2205 while ((entry != &map->header) && (entry->start < end)) { 2206 KASSERT((entry->flags & UVM_MAP_STATIC) == 0); 2207 2208 UVM_MAP_CLIP_END(map, entry, end); 2209 next = entry->next; 2210 len = entry->end - entry->start; 2211 2212 /* 2213 * unwire before removing addresses from the pmap; otherwise 2214 * unwiring will put the entries back into the pmap (XXX). 2215 */ 2216 2217 if (VM_MAPENT_ISWIRED(entry)) { 2218 uvm_map_entry_unwire(map, entry); 2219 } 2220 if (flags & UVM_FLAG_VAONLY) { 2221 2222 /* nothing */ 2223 2224 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2225 2226 /* 2227 * if the map is non-pageable, any pages mapped there 2228 * must be wired and entered with pmap_kenter_pa(), 2229 * and we should free any such pages immediately. 2230 * this is mostly used for kmem_map. 2231 */ 2232 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2233 2234 uvm_km_pgremove_intrsafe(map, entry->start, entry->end); 2235 } else if (UVM_ET_ISOBJ(entry) && 2236 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2237 panic("%s: kernel object %p %p\n", 2238 __func__, map, entry); 2239 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2240 /* 2241 * remove mappings the standard way. lock object 2242 * and/or amap to ensure vm_page state does not 2243 * change while in pmap_remove(). 2244 */ 2245 2246 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 2247 uvm_map_lock_entry(entry, RW_WRITER); 2248 #else 2249 uvm_map_lock_entry(entry, RW_READER); 2250 #endif 2251 pmap_remove(map->pmap, entry->start, entry->end); 2252 2253 /* 2254 * note: if map is dying, leave pmap_update() for 2255 * later. if the map is to be reused (exec) then 2256 * pmap_update() will be called. if the map is 2257 * being disposed of (exit) then pmap_destroy() 2258 * will be called. 2259 */ 2260 2261 if ((map->flags & VM_MAP_DYING) == 0) { 2262 pmap_update(vm_map_pmap(map)); 2263 } else { 2264 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2265 } 2266 2267 uvm_map_unlock_entry(entry); 2268 } 2269 2270 #if defined(UVMDEBUG) 2271 /* 2272 * check if there's remaining mapping, 2273 * which is a bug in caller. 2274 */ 2275 2276 vaddr_t va; 2277 for (va = entry->start; va < entry->end; 2278 va += PAGE_SIZE) { 2279 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2280 panic("%s: %#"PRIxVADDR" has mapping", 2281 __func__, va); 2282 } 2283 } 2284 2285 if (VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) { 2286 uvm_km_check_empty(map, entry->start, 2287 entry->end); 2288 } 2289 #endif /* defined(UVMDEBUG) */ 2290 2291 /* 2292 * remove entry from map and put it on our list of entries 2293 * that we've nuked. then go to next entry. 2294 */ 2295 2296 UVMHIST_LOG(maphist, " removed map entry %#jx", 2297 (uintptr_t)entry, 0, 0, 0); 2298 2299 /* critical! prevents stale hint */ 2300 SAVE_HINT(map, entry, entry->prev); 2301 2302 uvm_map_entry_unlink(map, entry); 2303 KASSERT(map->size >= len); 2304 map->size -= len; 2305 entry->prev = NULL; 2306 entry->next = first_entry; 2307 first_entry = entry; 2308 entry = next; 2309 } 2310 2311 uvm_map_check(map, "unmap_remove leave"); 2312 2313 /* 2314 * now we've cleaned up the map and are ready for the caller to drop 2315 * references to the mapped objects. 2316 */ 2317 2318 *entry_list = first_entry; 2319 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2320 2321 if (map->flags & VM_MAP_WANTVA) { 2322 mutex_enter(&map->misc_lock); 2323 map->flags &= ~VM_MAP_WANTVA; 2324 cv_broadcast(&map->cv); 2325 mutex_exit(&map->misc_lock); 2326 } 2327 } 2328 2329 /* 2330 * uvm_unmap_detach: drop references in a chain of map entries 2331 * 2332 * => we will free the map entries as we traverse the list. 2333 */ 2334 2335 void 2336 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2337 { 2338 struct vm_map_entry *next_entry; 2339 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 2340 2341 while (first_entry) { 2342 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2343 UVMHIST_LOG(maphist, 2344 " detach %#jx: amap=%#jx, obj=%#jx, submap?=%jd", 2345 (uintptr_t)first_entry, 2346 (uintptr_t)first_entry->aref.ar_amap, 2347 (uintptr_t)first_entry->object.uvm_obj, 2348 UVM_ET_ISSUBMAP(first_entry)); 2349 2350 /* 2351 * drop reference to amap, if we've got one 2352 */ 2353 2354 if (first_entry->aref.ar_amap) 2355 uvm_map_unreference_amap(first_entry, flags); 2356 2357 /* 2358 * drop reference to our backing object, if we've got one 2359 */ 2360 2361 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2362 if (UVM_ET_ISOBJ(first_entry) && 2363 first_entry->object.uvm_obj->pgops->pgo_detach) { 2364 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2365 (first_entry->object.uvm_obj); 2366 } 2367 next_entry = first_entry->next; 2368 uvm_mapent_free(first_entry); 2369 first_entry = next_entry; 2370 } 2371 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2372 } 2373 2374 /* 2375 * E X T R A C T I O N F U N C T I O N S 2376 */ 2377 2378 /* 2379 * uvm_map_reserve: reserve space in a vm_map for future use. 2380 * 2381 * => we reserve space in a map by putting a dummy map entry in the 2382 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2383 * => map should be unlocked (we will write lock it) 2384 * => we return true if we were able to reserve space 2385 * => XXXCDC: should be inline? 2386 */ 2387 2388 int 2389 uvm_map_reserve(struct vm_map *map, vsize_t size, 2390 vaddr_t offset /* hint for pmap_prefer */, 2391 vsize_t align /* alignment */, 2392 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2393 uvm_flag_t flags /* UVM_FLAG_FIXED or UVM_FLAG_COLORMATCH or 0 */) 2394 { 2395 UVMHIST_FUNC(__func__); 2396 UVMHIST_CALLARGS(maphist, "(map=%#jx, size=%#jx, offset=%#jx, addr=%#jx)", 2397 (uintptr_t)map, size, offset, (uintptr_t)raddr); 2398 2399 size = round_page(size); 2400 2401 /* 2402 * reserve some virtual space. 2403 */ 2404 2405 if (uvm_map(map, raddr, size, NULL, offset, align, 2406 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2407 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2408 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2409 return (false); 2410 } 2411 2412 UVMHIST_LOG(maphist, "<- done (*raddr=%#jx)", *raddr,0,0,0); 2413 return (true); 2414 } 2415 2416 /* 2417 * uvm_map_replace: replace a reserved (blank) area of memory with 2418 * real mappings. 2419 * 2420 * => caller must WRITE-LOCK the map 2421 * => we return true if replacement was a success 2422 * => we expect the newents chain to have nnewents entrys on it and 2423 * we expect newents->prev to point to the last entry on the list 2424 * => note newents is allowed to be NULL 2425 */ 2426 2427 static int 2428 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2429 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2430 struct vm_map_entry **oldentryp) 2431 { 2432 struct vm_map_entry *oldent, *last; 2433 2434 uvm_map_check(map, "map_replace entry"); 2435 2436 /* 2437 * first find the blank map entry at the specified address 2438 */ 2439 2440 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2441 return (false); 2442 } 2443 2444 /* 2445 * check to make sure we have a proper blank entry 2446 */ 2447 2448 if (end < oldent->end) { 2449 UVM_MAP_CLIP_END(map, oldent, end); 2450 } 2451 if (oldent->start != start || oldent->end != end || 2452 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2453 return (false); 2454 } 2455 2456 #ifdef DIAGNOSTIC 2457 2458 /* 2459 * sanity check the newents chain 2460 */ 2461 2462 { 2463 struct vm_map_entry *tmpent = newents; 2464 int nent = 0; 2465 vsize_t sz = 0; 2466 vaddr_t cur = start; 2467 2468 while (tmpent) { 2469 nent++; 2470 sz += tmpent->end - tmpent->start; 2471 if (tmpent->start < cur) 2472 panic("uvm_map_replace1"); 2473 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2474 panic("uvm_map_replace2: " 2475 "tmpent->start=%#"PRIxVADDR 2476 ", tmpent->end=%#"PRIxVADDR 2477 ", end=%#"PRIxVADDR, 2478 tmpent->start, tmpent->end, end); 2479 } 2480 cur = tmpent->end; 2481 if (tmpent->next) { 2482 if (tmpent->next->prev != tmpent) 2483 panic("uvm_map_replace3"); 2484 } else { 2485 if (newents->prev != tmpent) 2486 panic("uvm_map_replace4"); 2487 } 2488 tmpent = tmpent->next; 2489 } 2490 if (nent != nnewents) 2491 panic("uvm_map_replace5"); 2492 if (sz != nsize) 2493 panic("uvm_map_replace6"); 2494 } 2495 #endif 2496 2497 /* 2498 * map entry is a valid blank! replace it. (this does all the 2499 * work of map entry link/unlink...). 2500 */ 2501 2502 if (newents) { 2503 last = newents->prev; 2504 2505 /* critical: flush stale hints out of map */ 2506 SAVE_HINT(map, map->hint, newents); 2507 if (map->first_free == oldent) 2508 map->first_free = last; 2509 2510 last->next = oldent->next; 2511 last->next->prev = last; 2512 2513 /* Fix RB tree */ 2514 uvm_rb_remove(map, oldent); 2515 2516 newents->prev = oldent->prev; 2517 newents->prev->next = newents; 2518 map->nentries = map->nentries + (nnewents - 1); 2519 2520 /* Fixup the RB tree */ 2521 { 2522 int i; 2523 struct vm_map_entry *tmp; 2524 2525 tmp = newents; 2526 for (i = 0; i < nnewents && tmp; i++) { 2527 uvm_rb_insert(map, tmp); 2528 tmp = tmp->next; 2529 } 2530 } 2531 } else { 2532 /* NULL list of new entries: just remove the old one */ 2533 clear_hints(map, oldent); 2534 uvm_map_entry_unlink(map, oldent); 2535 } 2536 map->size -= end - start - nsize; 2537 2538 uvm_map_check(map, "map_replace leave"); 2539 2540 /* 2541 * now we can free the old blank entry and return. 2542 */ 2543 2544 *oldentryp = oldent; 2545 return (true); 2546 } 2547 2548 /* 2549 * uvm_map_extract: extract a mapping from a map and put it somewhere 2550 * (maybe removing the old mapping) 2551 * 2552 * => maps should be unlocked (we will write lock them) 2553 * => returns 0 on success, error code otherwise 2554 * => start must be page aligned 2555 * => len must be page sized 2556 * => flags: 2557 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2558 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2559 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2560 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2561 * UVM_EXTRACT_PROT_ALL: set prot to UVM_PROT_ALL as we go 2562 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2563 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2564 * be used from within the kernel in a kernel level map <<< 2565 */ 2566 2567 int 2568 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2569 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2570 { 2571 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2572 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2573 *deadentry, *oldentry; 2574 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2575 vsize_t elen __unused; 2576 int nchain, error, copy_ok; 2577 vsize_t nsize; 2578 UVMHIST_FUNC(__func__); 2579 UVMHIST_CALLARGS(maphist,"(srcmap=%#jx,start=%#jx, len=%#jx", 2580 (uintptr_t)srcmap, start, len, 0); 2581 UVMHIST_LOG(maphist," ...,dstmap=%#jx, flags=%#jx)", 2582 (uintptr_t)dstmap, flags, 0, 0); 2583 2584 /* 2585 * step 0: sanity check: start must be on a page boundary, length 2586 * must be page sized. can't ask for CONTIG/QREF if you asked for 2587 * REMOVE. 2588 */ 2589 2590 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2591 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2592 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2593 2594 /* 2595 * step 1: reserve space in the target map for the extracted area 2596 */ 2597 2598 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2599 dstaddr = vm_map_min(dstmap); 2600 if (!uvm_map_reserve(dstmap, len, start, 2601 atop(start) & uvmexp.colormask, &dstaddr, 2602 UVM_FLAG_COLORMATCH)) 2603 return (ENOMEM); 2604 KASSERT((atop(start ^ dstaddr) & uvmexp.colormask) == 0); 2605 *dstaddrp = dstaddr; /* pass address back to caller */ 2606 UVMHIST_LOG(maphist, " dstaddr=%#jx", dstaddr,0,0,0); 2607 } else { 2608 dstaddr = *dstaddrp; 2609 } 2610 2611 /* 2612 * step 2: setup for the extraction process loop by init'ing the 2613 * map entry chain, locking src map, and looking up the first useful 2614 * entry in the map. 2615 */ 2616 2617 end = start + len; 2618 newend = dstaddr + len; 2619 chain = endchain = NULL; 2620 nchain = 0; 2621 nsize = 0; 2622 vm_map_lock(srcmap); 2623 2624 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2625 2626 /* "start" is within an entry */ 2627 if (flags & UVM_EXTRACT_QREF) { 2628 2629 /* 2630 * for quick references we don't clip the entry, so 2631 * the entry may map space "before" the starting 2632 * virtual address... this is the "fudge" factor 2633 * (which can be non-zero only the first time 2634 * through the "while" loop in step 3). 2635 */ 2636 2637 fudge = start - entry->start; 2638 } else { 2639 2640 /* 2641 * normal reference: we clip the map to fit (thus 2642 * fudge is zero) 2643 */ 2644 2645 UVM_MAP_CLIP_START(srcmap, entry, start); 2646 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2647 fudge = 0; 2648 } 2649 } else { 2650 2651 /* "start" is not within an entry ... skip to next entry */ 2652 if (flags & UVM_EXTRACT_CONTIG) { 2653 error = EINVAL; 2654 goto bad; /* definite hole here ... */ 2655 } 2656 2657 entry = entry->next; 2658 fudge = 0; 2659 } 2660 2661 /* save values from srcmap for step 6 */ 2662 orig_entry = entry; 2663 orig_fudge = fudge; 2664 2665 /* 2666 * step 3: now start looping through the map entries, extracting 2667 * as we go. 2668 */ 2669 2670 while (entry->start < end && entry != &srcmap->header) { 2671 2672 /* if we are not doing a quick reference, clip it */ 2673 if ((flags & UVM_EXTRACT_QREF) == 0) 2674 UVM_MAP_CLIP_END(srcmap, entry, end); 2675 2676 /* clear needs_copy (allow chunking) */ 2677 if (UVM_ET_ISNEEDSCOPY(entry)) { 2678 amap_copy(srcmap, entry, 2679 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2680 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2681 error = ENOMEM; 2682 goto bad; 2683 } 2684 2685 /* amap_copy could clip (during chunk)! update fudge */ 2686 if (fudge) { 2687 fudge = start - entry->start; 2688 orig_fudge = fudge; 2689 } 2690 } 2691 2692 /* calculate the offset of this from "start" */ 2693 oldoffset = (entry->start + fudge) - start; 2694 2695 /* allocate a new map entry */ 2696 newentry = uvm_mapent_alloc(dstmap, 0); 2697 if (newentry == NULL) { 2698 error = ENOMEM; 2699 goto bad; 2700 } 2701 2702 /* set up new map entry */ 2703 newentry->next = NULL; 2704 newentry->prev = endchain; 2705 newentry->start = dstaddr + oldoffset; 2706 newentry->end = 2707 newentry->start + (entry->end - (entry->start + fudge)); 2708 if (newentry->end > newend || newentry->end < newentry->start) 2709 newentry->end = newend; 2710 newentry->object.uvm_obj = entry->object.uvm_obj; 2711 if (newentry->object.uvm_obj) { 2712 if (newentry->object.uvm_obj->pgops->pgo_reference) 2713 newentry->object.uvm_obj->pgops-> 2714 pgo_reference(newentry->object.uvm_obj); 2715 newentry->offset = entry->offset + fudge; 2716 } else { 2717 newentry->offset = 0; 2718 } 2719 newentry->etype = entry->etype; 2720 if (flags & UVM_EXTRACT_PROT_ALL) { 2721 newentry->protection = newentry->max_protection = 2722 UVM_PROT_ALL; 2723 } else { 2724 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2725 entry->max_protection : entry->protection; 2726 newentry->max_protection = entry->max_protection; 2727 } 2728 newentry->inheritance = entry->inheritance; 2729 newentry->wired_count = 0; 2730 newentry->aref.ar_amap = entry->aref.ar_amap; 2731 if (newentry->aref.ar_amap) { 2732 newentry->aref.ar_pageoff = 2733 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2734 uvm_map_reference_amap(newentry, AMAP_SHARED | 2735 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2736 } else { 2737 newentry->aref.ar_pageoff = 0; 2738 } 2739 newentry->advice = entry->advice; 2740 if ((flags & UVM_EXTRACT_QREF) != 0) { 2741 newentry->flags |= UVM_MAP_NOMERGE; 2742 } 2743 2744 /* now link it on the chain */ 2745 nchain++; 2746 nsize += newentry->end - newentry->start; 2747 if (endchain == NULL) { 2748 chain = endchain = newentry; 2749 } else { 2750 endchain->next = newentry; 2751 endchain = newentry; 2752 } 2753 2754 /* end of 'while' loop! */ 2755 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2756 (entry->next == &srcmap->header || 2757 entry->next->start != entry->end)) { 2758 error = EINVAL; 2759 goto bad; 2760 } 2761 entry = entry->next; 2762 fudge = 0; 2763 } 2764 2765 /* 2766 * step 4: close off chain (in format expected by uvm_map_replace) 2767 */ 2768 2769 if (chain) 2770 chain->prev = endchain; 2771 2772 /* 2773 * step 5: attempt to lock the dest map so we can pmap_copy. 2774 * note usage of copy_ok: 2775 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2776 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2777 */ 2778 2779 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2780 copy_ok = 1; 2781 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2782 nchain, nsize, &resentry)) { 2783 if (srcmap != dstmap) 2784 vm_map_unlock(dstmap); 2785 error = EIO; 2786 goto bad; 2787 } 2788 } else { 2789 copy_ok = 0; 2790 /* replace defered until step 7 */ 2791 } 2792 2793 /* 2794 * step 6: traverse the srcmap a second time to do the following: 2795 * - if we got a lock on the dstmap do pmap_copy 2796 * - if UVM_EXTRACT_REMOVE remove the entries 2797 * we make use of orig_entry and orig_fudge (saved in step 2) 2798 */ 2799 2800 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2801 2802 /* purge possible stale hints from srcmap */ 2803 if (flags & UVM_EXTRACT_REMOVE) { 2804 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2805 if (srcmap->first_free != &srcmap->header && 2806 srcmap->first_free->start >= start) 2807 srcmap->first_free = orig_entry->prev; 2808 } 2809 2810 entry = orig_entry; 2811 fudge = orig_fudge; 2812 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2813 2814 while (entry->start < end && entry != &srcmap->header) { 2815 if (copy_ok) { 2816 oldoffset = (entry->start + fudge) - start; 2817 elen = MIN(end, entry->end) - 2818 (entry->start + fudge); 2819 pmap_copy(dstmap->pmap, srcmap->pmap, 2820 dstaddr + oldoffset, elen, 2821 entry->start + fudge); 2822 } 2823 2824 /* we advance "entry" in the following if statement */ 2825 if (flags & UVM_EXTRACT_REMOVE) { 2826 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 2827 uvm_map_lock_entry(entry, RW_WRITER); 2828 #else 2829 uvm_map_lock_entry(entry, RW_READER); 2830 #endif 2831 pmap_remove(srcmap->pmap, entry->start, 2832 entry->end); 2833 uvm_map_unlock_entry(entry); 2834 oldentry = entry; /* save entry */ 2835 entry = entry->next; /* advance */ 2836 uvm_map_entry_unlink(srcmap, oldentry); 2837 /* add to dead list */ 2838 oldentry->next = deadentry; 2839 deadentry = oldentry; 2840 } else { 2841 entry = entry->next; /* advance */ 2842 } 2843 2844 /* end of 'while' loop */ 2845 fudge = 0; 2846 } 2847 pmap_update(srcmap->pmap); 2848 2849 /* 2850 * unlock dstmap. we will dispose of deadentry in 2851 * step 7 if needed 2852 */ 2853 2854 if (copy_ok && srcmap != dstmap) 2855 vm_map_unlock(dstmap); 2856 2857 } else { 2858 deadentry = NULL; 2859 } 2860 2861 /* 2862 * step 7: we are done with the source map, unlock. if copy_ok 2863 * is 0 then we have not replaced the dummy mapping in dstmap yet 2864 * and we need to do so now. 2865 */ 2866 2867 vm_map_unlock(srcmap); 2868 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 2869 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 2870 2871 /* now do the replacement if we didn't do it in step 5 */ 2872 if (copy_ok == 0) { 2873 vm_map_lock(dstmap); 2874 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2875 nchain, nsize, &resentry); 2876 vm_map_unlock(dstmap); 2877 2878 if (error == false) { 2879 error = EIO; 2880 goto bad2; 2881 } 2882 } 2883 2884 if (resentry != NULL) 2885 uvm_mapent_free(resentry); 2886 2887 return (0); 2888 2889 /* 2890 * bad: failure recovery 2891 */ 2892 bad: 2893 vm_map_unlock(srcmap); 2894 bad2: /* src already unlocked */ 2895 if (chain) 2896 uvm_unmap_detach(chain, 2897 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 2898 2899 if (resentry != NULL) 2900 uvm_mapent_free(resentry); 2901 2902 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2903 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 2904 } 2905 return (error); 2906 } 2907 2908 /* end of extraction functions */ 2909 2910 /* 2911 * uvm_map_submap: punch down part of a map into a submap 2912 * 2913 * => only the kernel_map is allowed to be submapped 2914 * => the purpose of submapping is to break up the locking granularity 2915 * of a larger map 2916 * => the range specified must have been mapped previously with a uvm_map() 2917 * call [with uobj==NULL] to create a blank map entry in the main map. 2918 * [And it had better still be blank!] 2919 * => maps which contain submaps should never be copied or forked. 2920 * => to remove a submap, use uvm_unmap() on the main map 2921 * and then uvm_map_deallocate() the submap. 2922 * => main map must be unlocked. 2923 * => submap must have been init'd and have a zero reference count. 2924 * [need not be locked as we don't actually reference it] 2925 */ 2926 2927 int 2928 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 2929 struct vm_map *submap) 2930 { 2931 struct vm_map_entry *entry; 2932 int error; 2933 2934 vm_map_lock(map); 2935 VM_MAP_RANGE_CHECK(map, start, end); 2936 2937 if (uvm_map_lookup_entry(map, start, &entry)) { 2938 UVM_MAP_CLIP_START(map, entry, start); 2939 UVM_MAP_CLIP_END(map, entry, end); /* to be safe */ 2940 } else { 2941 entry = NULL; 2942 } 2943 2944 if (entry != NULL && 2945 entry->start == start && entry->end == end && 2946 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 2947 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 2948 entry->etype |= UVM_ET_SUBMAP; 2949 entry->object.sub_map = submap; 2950 entry->offset = 0; 2951 uvm_map_reference(submap); 2952 error = 0; 2953 } else { 2954 error = EINVAL; 2955 } 2956 vm_map_unlock(map); 2957 2958 return error; 2959 } 2960 2961 /* 2962 * uvm_map_protect_user: change map protection on behalf of the user. 2963 * Enforces PAX settings as necessary. 2964 */ 2965 int 2966 uvm_map_protect_user(struct lwp *l, vaddr_t start, vaddr_t end, 2967 vm_prot_t new_prot) 2968 { 2969 int error; 2970 2971 if ((error = PAX_MPROTECT_VALIDATE(l, new_prot))) 2972 return error; 2973 2974 return uvm_map_protect(&l->l_proc->p_vmspace->vm_map, start, end, 2975 new_prot, false); 2976 } 2977 2978 2979 /* 2980 * uvm_map_protect: change map protection 2981 * 2982 * => set_max means set max_protection. 2983 * => map must be unlocked. 2984 */ 2985 2986 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 2987 ~VM_PROT_WRITE : VM_PROT_ALL) 2988 2989 int 2990 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 2991 vm_prot_t new_prot, bool set_max) 2992 { 2993 struct vm_map_entry *current, *entry; 2994 int error = 0; 2995 UVMHIST_FUNC(__func__); 2996 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_prot=%#jx)", 2997 (uintptr_t)map, start, end, new_prot); 2998 2999 vm_map_lock(map); 3000 VM_MAP_RANGE_CHECK(map, start, end); 3001 if (uvm_map_lookup_entry(map, start, &entry)) { 3002 UVM_MAP_CLIP_START(map, entry, start); 3003 } else { 3004 entry = entry->next; 3005 } 3006 3007 /* 3008 * make a first pass to check for protection violations. 3009 */ 3010 3011 current = entry; 3012 while ((current != &map->header) && (current->start < end)) { 3013 if (UVM_ET_ISSUBMAP(current)) { 3014 error = EINVAL; 3015 goto out; 3016 } 3017 if ((new_prot & current->max_protection) != new_prot) { 3018 error = EACCES; 3019 goto out; 3020 } 3021 /* 3022 * Don't allow VM_PROT_EXECUTE to be set on entries that 3023 * point to vnodes that are associated with a NOEXEC file 3024 * system. 3025 */ 3026 if (UVM_ET_ISOBJ(current) && 3027 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3028 struct vnode *vp = 3029 (struct vnode *) current->object.uvm_obj; 3030 3031 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3032 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3033 error = EACCES; 3034 goto out; 3035 } 3036 } 3037 3038 current = current->next; 3039 } 3040 3041 /* go back and fix up protections (no need to clip this time). */ 3042 3043 current = entry; 3044 while ((current != &map->header) && (current->start < end)) { 3045 vm_prot_t old_prot; 3046 3047 UVM_MAP_CLIP_END(map, current, end); 3048 old_prot = current->protection; 3049 if (set_max) 3050 current->protection = 3051 (current->max_protection = new_prot) & old_prot; 3052 else 3053 current->protection = new_prot; 3054 3055 /* 3056 * update physical map if necessary. worry about copy-on-write 3057 * here -- CHECK THIS XXX 3058 */ 3059 3060 if (current->protection != old_prot) { 3061 /* update pmap! */ 3062 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 3063 uvm_map_lock_entry(current, RW_WRITER); 3064 #else 3065 uvm_map_lock_entry(current, RW_READER); 3066 #endif 3067 pmap_protect(map->pmap, current->start, current->end, 3068 current->protection & MASK(current)); 3069 uvm_map_unlock_entry(current); 3070 3071 /* 3072 * If this entry points at a vnode, and the 3073 * protection includes VM_PROT_EXECUTE, mark 3074 * the vnode as VEXECMAP. 3075 */ 3076 if (UVM_ET_ISOBJ(current)) { 3077 struct uvm_object *uobj = 3078 current->object.uvm_obj; 3079 3080 if (UVM_OBJ_IS_VNODE(uobj) && 3081 (current->protection & VM_PROT_EXECUTE)) { 3082 vn_markexec((struct vnode *) uobj); 3083 } 3084 } 3085 } 3086 3087 /* 3088 * If the map is configured to lock any future mappings, 3089 * wire this entry now if the old protection was VM_PROT_NONE 3090 * and the new protection is not VM_PROT_NONE. 3091 */ 3092 3093 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3094 VM_MAPENT_ISWIRED(current) == 0 && 3095 old_prot == VM_PROT_NONE && 3096 new_prot != VM_PROT_NONE) { 3097 3098 /* 3099 * We must call pmap_update() here because the 3100 * pmap_protect() call above might have removed some 3101 * pmap entries and uvm_map_pageable() might create 3102 * some new pmap entries that rely on the prior 3103 * removals being completely finished. 3104 */ 3105 3106 pmap_update(map->pmap); 3107 3108 if (uvm_map_pageable(map, current->start, 3109 current->end, false, 3110 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3111 3112 /* 3113 * If locking the entry fails, remember the 3114 * error if it's the first one. Note we 3115 * still continue setting the protection in 3116 * the map, but will return the error 3117 * condition regardless. 3118 * 3119 * XXX Ignore what the actual error is, 3120 * XXX just call it a resource shortage 3121 * XXX so that it doesn't get confused 3122 * XXX what uvm_map_protect() itself would 3123 * XXX normally return. 3124 */ 3125 3126 error = ENOMEM; 3127 } 3128 } 3129 current = current->next; 3130 } 3131 pmap_update(map->pmap); 3132 3133 out: 3134 vm_map_unlock(map); 3135 3136 UVMHIST_LOG(maphist, "<- done, error=%jd",error,0,0,0); 3137 return error; 3138 } 3139 3140 #undef MASK 3141 3142 /* 3143 * uvm_map_inherit: set inheritance code for range of addrs in map. 3144 * 3145 * => map must be unlocked 3146 * => note that the inherit code is used during a "fork". see fork 3147 * code for details. 3148 */ 3149 3150 int 3151 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3152 vm_inherit_t new_inheritance) 3153 { 3154 struct vm_map_entry *entry, *temp_entry; 3155 UVMHIST_FUNC(__func__); 3156 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_inh=%#jx)", 3157 (uintptr_t)map, start, end, new_inheritance); 3158 3159 switch (new_inheritance) { 3160 case MAP_INHERIT_NONE: 3161 case MAP_INHERIT_COPY: 3162 case MAP_INHERIT_SHARE: 3163 case MAP_INHERIT_ZERO: 3164 break; 3165 default: 3166 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3167 return EINVAL; 3168 } 3169 3170 vm_map_lock(map); 3171 VM_MAP_RANGE_CHECK(map, start, end); 3172 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3173 entry = temp_entry; 3174 UVM_MAP_CLIP_START(map, entry, start); 3175 } else { 3176 entry = temp_entry->next; 3177 } 3178 while ((entry != &map->header) && (entry->start < end)) { 3179 UVM_MAP_CLIP_END(map, entry, end); 3180 entry->inheritance = new_inheritance; 3181 entry = entry->next; 3182 } 3183 vm_map_unlock(map); 3184 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3185 return 0; 3186 } 3187 3188 /* 3189 * uvm_map_advice: set advice code for range of addrs in map. 3190 * 3191 * => map must be unlocked 3192 */ 3193 3194 int 3195 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3196 { 3197 struct vm_map_entry *entry, *temp_entry; 3198 UVMHIST_FUNC(__func__); 3199 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_adv=%#jx)", 3200 (uintptr_t)map, start, end, new_advice); 3201 3202 vm_map_lock(map); 3203 VM_MAP_RANGE_CHECK(map, start, end); 3204 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3205 entry = temp_entry; 3206 UVM_MAP_CLIP_START(map, entry, start); 3207 } else { 3208 entry = temp_entry->next; 3209 } 3210 3211 /* 3212 * XXXJRT: disallow holes? 3213 */ 3214 3215 while ((entry != &map->header) && (entry->start < end)) { 3216 UVM_MAP_CLIP_END(map, entry, end); 3217 3218 switch (new_advice) { 3219 case MADV_NORMAL: 3220 case MADV_RANDOM: 3221 case MADV_SEQUENTIAL: 3222 /* nothing special here */ 3223 break; 3224 3225 default: 3226 vm_map_unlock(map); 3227 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3228 return EINVAL; 3229 } 3230 entry->advice = new_advice; 3231 entry = entry->next; 3232 } 3233 3234 vm_map_unlock(map); 3235 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3236 return 0; 3237 } 3238 3239 /* 3240 * uvm_map_willneed: apply MADV_WILLNEED 3241 */ 3242 3243 int 3244 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3245 { 3246 struct vm_map_entry *entry; 3247 UVMHIST_FUNC(__func__); 3248 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx)", 3249 (uintptr_t)map, start, end, 0); 3250 3251 vm_map_lock_read(map); 3252 VM_MAP_RANGE_CHECK(map, start, end); 3253 if (!uvm_map_lookup_entry(map, start, &entry)) { 3254 entry = entry->next; 3255 } 3256 while (entry->start < end) { 3257 struct vm_amap * const amap = entry->aref.ar_amap; 3258 struct uvm_object * const uobj = entry->object.uvm_obj; 3259 3260 KASSERT(entry != &map->header); 3261 KASSERT(start < entry->end); 3262 /* 3263 * For now, we handle only the easy but commonly-requested case. 3264 * ie. start prefetching of backing uobj pages. 3265 * 3266 * XXX It might be useful to pmap_enter() the already-in-core 3267 * pages by inventing a "weak" mode for uvm_fault() which would 3268 * only do the PGO_LOCKED pgo_get(). 3269 */ 3270 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3271 off_t offset; 3272 off_t size; 3273 3274 offset = entry->offset; 3275 if (start < entry->start) { 3276 offset += entry->start - start; 3277 } 3278 size = entry->offset + (entry->end - entry->start); 3279 if (entry->end < end) { 3280 size -= end - entry->end; 3281 } 3282 uvm_readahead(uobj, offset, size); 3283 } 3284 entry = entry->next; 3285 } 3286 vm_map_unlock_read(map); 3287 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3288 return 0; 3289 } 3290 3291 /* 3292 * uvm_map_pageable: sets the pageability of a range in a map. 3293 * 3294 * => wires map entries. should not be used for transient page locking. 3295 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3296 * => regions specified as not pageable require lock-down (wired) memory 3297 * and page tables. 3298 * => map must never be read-locked 3299 * => if islocked is true, map is already write-locked 3300 * => we always unlock the map, since we must downgrade to a read-lock 3301 * to call uvm_fault_wire() 3302 * => XXXCDC: check this and try and clean it up. 3303 */ 3304 3305 int 3306 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3307 bool new_pageable, int lockflags) 3308 { 3309 struct vm_map_entry *entry, *start_entry, *failed_entry; 3310 int rv; 3311 #ifdef DIAGNOSTIC 3312 u_int timestamp_save; 3313 #endif 3314 UVMHIST_FUNC(__func__); 3315 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_pageable=%ju)", 3316 (uintptr_t)map, start, end, new_pageable); 3317 KASSERT(map->flags & VM_MAP_PAGEABLE); 3318 3319 if ((lockflags & UVM_LK_ENTER) == 0) 3320 vm_map_lock(map); 3321 VM_MAP_RANGE_CHECK(map, start, end); 3322 3323 /* 3324 * only one pageability change may take place at one time, since 3325 * uvm_fault_wire assumes it will be called only once for each 3326 * wiring/unwiring. therefore, we have to make sure we're actually 3327 * changing the pageability for the entire region. we do so before 3328 * making any changes. 3329 */ 3330 3331 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3332 if ((lockflags & UVM_LK_EXIT) == 0) 3333 vm_map_unlock(map); 3334 3335 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3336 return EFAULT; 3337 } 3338 entry = start_entry; 3339 3340 if (start == end) { /* nothing required */ 3341 if ((lockflags & UVM_LK_EXIT) == 0) 3342 vm_map_unlock(map); 3343 3344 UVMHIST_LOG(maphist,"<- done (nothing)",0,0,0,0); 3345 return 0; 3346 } 3347 3348 /* 3349 * handle wiring and unwiring separately. 3350 */ 3351 3352 if (new_pageable) { /* unwire */ 3353 UVM_MAP_CLIP_START(map, entry, start); 3354 3355 /* 3356 * unwiring. first ensure that the range to be unwired is 3357 * really wired down and that there are no holes. 3358 */ 3359 3360 while ((entry != &map->header) && (entry->start < end)) { 3361 if (entry->wired_count == 0 || 3362 (entry->end < end && 3363 (entry->next == &map->header || 3364 entry->next->start > entry->end))) { 3365 if ((lockflags & UVM_LK_EXIT) == 0) 3366 vm_map_unlock(map); 3367 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3368 return EINVAL; 3369 } 3370 entry = entry->next; 3371 } 3372 3373 /* 3374 * POSIX 1003.1b - a single munlock call unlocks a region, 3375 * regardless of the number of mlock calls made on that 3376 * region. 3377 */ 3378 3379 entry = start_entry; 3380 while ((entry != &map->header) && (entry->start < end)) { 3381 UVM_MAP_CLIP_END(map, entry, end); 3382 if (VM_MAPENT_ISWIRED(entry)) 3383 uvm_map_entry_unwire(map, entry); 3384 entry = entry->next; 3385 } 3386 if ((lockflags & UVM_LK_EXIT) == 0) 3387 vm_map_unlock(map); 3388 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3389 return 0; 3390 } 3391 3392 /* 3393 * wire case: in two passes [XXXCDC: ugly block of code here] 3394 * 3395 * 1: holding the write lock, we create any anonymous maps that need 3396 * to be created. then we clip each map entry to the region to 3397 * be wired and increment its wiring count. 3398 * 3399 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3400 * in the pages for any newly wired area (wired_count == 1). 3401 * 3402 * downgrading to a read lock for uvm_fault_wire avoids a possible 3403 * deadlock with another thread that may have faulted on one of 3404 * the pages to be wired (it would mark the page busy, blocking 3405 * us, then in turn block on the map lock that we hold). because 3406 * of problems in the recursive lock package, we cannot upgrade 3407 * to a write lock in vm_map_lookup. thus, any actions that 3408 * require the write lock must be done beforehand. because we 3409 * keep the read lock on the map, the copy-on-write status of the 3410 * entries we modify here cannot change. 3411 */ 3412 3413 while ((entry != &map->header) && (entry->start < end)) { 3414 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3415 3416 /* 3417 * perform actions of vm_map_lookup that need the 3418 * write lock on the map: create an anonymous map 3419 * for a copy-on-write region, or an anonymous map 3420 * for a zero-fill region. (XXXCDC: submap case 3421 * ok?) 3422 */ 3423 3424 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3425 if (UVM_ET_ISNEEDSCOPY(entry) && 3426 ((entry->max_protection & VM_PROT_WRITE) || 3427 (entry->object.uvm_obj == NULL))) { 3428 amap_copy(map, entry, 0, start, end); 3429 /* XXXCDC: wait OK? */ 3430 } 3431 } 3432 } 3433 UVM_MAP_CLIP_START(map, entry, start); 3434 UVM_MAP_CLIP_END(map, entry, end); 3435 entry->wired_count++; 3436 3437 /* 3438 * Check for holes 3439 */ 3440 3441 if (entry->protection == VM_PROT_NONE || 3442 (entry->end < end && 3443 (entry->next == &map->header || 3444 entry->next->start > entry->end))) { 3445 3446 /* 3447 * found one. amap creation actions do not need to 3448 * be undone, but the wired counts need to be restored. 3449 */ 3450 3451 while (entry != &map->header && entry->end > start) { 3452 entry->wired_count--; 3453 entry = entry->prev; 3454 } 3455 if ((lockflags & UVM_LK_EXIT) == 0) 3456 vm_map_unlock(map); 3457 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3458 return EINVAL; 3459 } 3460 entry = entry->next; 3461 } 3462 3463 /* 3464 * Pass 2. 3465 */ 3466 3467 #ifdef DIAGNOSTIC 3468 timestamp_save = map->timestamp; 3469 #endif 3470 vm_map_busy(map); 3471 vm_map_unlock(map); 3472 3473 rv = 0; 3474 entry = start_entry; 3475 while (entry != &map->header && entry->start < end) { 3476 if (entry->wired_count == 1) { 3477 rv = uvm_fault_wire(map, entry->start, entry->end, 3478 entry->max_protection, 1); 3479 if (rv) { 3480 3481 /* 3482 * wiring failed. break out of the loop. 3483 * we'll clean up the map below, once we 3484 * have a write lock again. 3485 */ 3486 3487 break; 3488 } 3489 } 3490 entry = entry->next; 3491 } 3492 3493 if (rv) { /* failed? */ 3494 3495 /* 3496 * Get back to an exclusive (write) lock. 3497 */ 3498 3499 vm_map_lock(map); 3500 vm_map_unbusy(map); 3501 3502 #ifdef DIAGNOSTIC 3503 if (timestamp_save + 1 != map->timestamp) 3504 panic("uvm_map_pageable: stale map"); 3505 #endif 3506 3507 /* 3508 * first drop the wiring count on all the entries 3509 * which haven't actually been wired yet. 3510 */ 3511 3512 failed_entry = entry; 3513 while (entry != &map->header && entry->start < end) { 3514 entry->wired_count--; 3515 entry = entry->next; 3516 } 3517 3518 /* 3519 * now, unwire all the entries that were successfully 3520 * wired above. 3521 */ 3522 3523 entry = start_entry; 3524 while (entry != failed_entry) { 3525 entry->wired_count--; 3526 if (VM_MAPENT_ISWIRED(entry) == 0) 3527 uvm_map_entry_unwire(map, entry); 3528 entry = entry->next; 3529 } 3530 if ((lockflags & UVM_LK_EXIT) == 0) 3531 vm_map_unlock(map); 3532 UVMHIST_LOG(maphist, "<- done (RV=%jd)", rv,0,0,0); 3533 return (rv); 3534 } 3535 3536 if ((lockflags & UVM_LK_EXIT) == 0) { 3537 vm_map_unbusy(map); 3538 } else { 3539 3540 /* 3541 * Get back to an exclusive (write) lock. 3542 */ 3543 3544 vm_map_lock(map); 3545 vm_map_unbusy(map); 3546 } 3547 3548 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3549 return 0; 3550 } 3551 3552 /* 3553 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3554 * all mapped regions. 3555 * 3556 * => map must not be locked. 3557 * => if no flags are specified, all regions are unwired. 3558 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3559 */ 3560 3561 int 3562 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3563 { 3564 struct vm_map_entry *entry, *failed_entry; 3565 vsize_t size; 3566 int rv; 3567 #ifdef DIAGNOSTIC 3568 u_int timestamp_save; 3569 #endif 3570 UVMHIST_FUNC(__func__); 3571 UVMHIST_CALLARGS(maphist,"(map=%#jx,flags=%#jx)", (uintptr_t)map, flags, 3572 0, 0); 3573 3574 KASSERT(map->flags & VM_MAP_PAGEABLE); 3575 3576 vm_map_lock(map); 3577 3578 /* 3579 * handle wiring and unwiring separately. 3580 */ 3581 3582 if (flags == 0) { /* unwire */ 3583 3584 /* 3585 * POSIX 1003.1b -- munlockall unlocks all regions, 3586 * regardless of how many times mlockall has been called. 3587 */ 3588 3589 for (entry = map->header.next; entry != &map->header; 3590 entry = entry->next) { 3591 if (VM_MAPENT_ISWIRED(entry)) 3592 uvm_map_entry_unwire(map, entry); 3593 } 3594 map->flags &= ~VM_MAP_WIREFUTURE; 3595 vm_map_unlock(map); 3596 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3597 return 0; 3598 } 3599 3600 if (flags & MCL_FUTURE) { 3601 3602 /* 3603 * must wire all future mappings; remember this. 3604 */ 3605 3606 map->flags |= VM_MAP_WIREFUTURE; 3607 } 3608 3609 if ((flags & MCL_CURRENT) == 0) { 3610 3611 /* 3612 * no more work to do! 3613 */ 3614 3615 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3616 vm_map_unlock(map); 3617 return 0; 3618 } 3619 3620 /* 3621 * wire case: in three passes [XXXCDC: ugly block of code here] 3622 * 3623 * 1: holding the write lock, count all pages mapped by non-wired 3624 * entries. if this would cause us to go over our limit, we fail. 3625 * 3626 * 2: still holding the write lock, we create any anonymous maps that 3627 * need to be created. then we increment its wiring count. 3628 * 3629 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3630 * in the pages for any newly wired area (wired_count == 1). 3631 * 3632 * downgrading to a read lock for uvm_fault_wire avoids a possible 3633 * deadlock with another thread that may have faulted on one of 3634 * the pages to be wired (it would mark the page busy, blocking 3635 * us, then in turn block on the map lock that we hold). because 3636 * of problems in the recursive lock package, we cannot upgrade 3637 * to a write lock in vm_map_lookup. thus, any actions that 3638 * require the write lock must be done beforehand. because we 3639 * keep the read lock on the map, the copy-on-write status of the 3640 * entries we modify here cannot change. 3641 */ 3642 3643 for (size = 0, entry = map->header.next; entry != &map->header; 3644 entry = entry->next) { 3645 if (entry->protection != VM_PROT_NONE && 3646 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3647 size += entry->end - entry->start; 3648 } 3649 } 3650 3651 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3652 vm_map_unlock(map); 3653 return ENOMEM; 3654 } 3655 3656 if (limit != 0 && 3657 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3658 vm_map_unlock(map); 3659 return ENOMEM; 3660 } 3661 3662 /* 3663 * Pass 2. 3664 */ 3665 3666 for (entry = map->header.next; entry != &map->header; 3667 entry = entry->next) { 3668 if (entry->protection == VM_PROT_NONE) 3669 continue; 3670 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3671 3672 /* 3673 * perform actions of vm_map_lookup that need the 3674 * write lock on the map: create an anonymous map 3675 * for a copy-on-write region, or an anonymous map 3676 * for a zero-fill region. (XXXCDC: submap case 3677 * ok?) 3678 */ 3679 3680 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3681 if (UVM_ET_ISNEEDSCOPY(entry) && 3682 ((entry->max_protection & VM_PROT_WRITE) || 3683 (entry->object.uvm_obj == NULL))) { 3684 amap_copy(map, entry, 0, entry->start, 3685 entry->end); 3686 /* XXXCDC: wait OK? */ 3687 } 3688 } 3689 } 3690 entry->wired_count++; 3691 } 3692 3693 /* 3694 * Pass 3. 3695 */ 3696 3697 #ifdef DIAGNOSTIC 3698 timestamp_save = map->timestamp; 3699 #endif 3700 vm_map_busy(map); 3701 vm_map_unlock(map); 3702 3703 rv = 0; 3704 for (entry = map->header.next; entry != &map->header; 3705 entry = entry->next) { 3706 if (entry->wired_count == 1) { 3707 rv = uvm_fault_wire(map, entry->start, entry->end, 3708 entry->max_protection, 1); 3709 if (rv) { 3710 3711 /* 3712 * wiring failed. break out of the loop. 3713 * we'll clean up the map below, once we 3714 * have a write lock again. 3715 */ 3716 3717 break; 3718 } 3719 } 3720 } 3721 3722 if (rv) { 3723 3724 /* 3725 * Get back an exclusive (write) lock. 3726 */ 3727 3728 vm_map_lock(map); 3729 vm_map_unbusy(map); 3730 3731 #ifdef DIAGNOSTIC 3732 if (timestamp_save + 1 != map->timestamp) 3733 panic("uvm_map_pageable_all: stale map"); 3734 #endif 3735 3736 /* 3737 * first drop the wiring count on all the entries 3738 * which haven't actually been wired yet. 3739 * 3740 * Skip VM_PROT_NONE entries like we did above. 3741 */ 3742 3743 failed_entry = entry; 3744 for (/* nothing */; entry != &map->header; 3745 entry = entry->next) { 3746 if (entry->protection == VM_PROT_NONE) 3747 continue; 3748 entry->wired_count--; 3749 } 3750 3751 /* 3752 * now, unwire all the entries that were successfully 3753 * wired above. 3754 * 3755 * Skip VM_PROT_NONE entries like we did above. 3756 */ 3757 3758 for (entry = map->header.next; entry != failed_entry; 3759 entry = entry->next) { 3760 if (entry->protection == VM_PROT_NONE) 3761 continue; 3762 entry->wired_count--; 3763 if (VM_MAPENT_ISWIRED(entry)) 3764 uvm_map_entry_unwire(map, entry); 3765 } 3766 vm_map_unlock(map); 3767 UVMHIST_LOG(maphist,"<- done (RV=%jd)", rv,0,0,0); 3768 return (rv); 3769 } 3770 3771 vm_map_unbusy(map); 3772 3773 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3774 return 0; 3775 } 3776 3777 /* 3778 * uvm_map_clean: clean out a map range 3779 * 3780 * => valid flags: 3781 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3782 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3783 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3784 * if (flags & PGO_FREE): any cached pages are freed after clean 3785 * => returns an error if any part of the specified range isn't mapped 3786 * => never a need to flush amap layer since the anonymous memory has 3787 * no permanent home, but may deactivate pages there 3788 * => called from sys_msync() and sys_madvise() 3789 * => caller must not write-lock map (read OK). 3790 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3791 */ 3792 3793 int 3794 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3795 { 3796 struct vm_map_entry *current, *entry; 3797 struct uvm_object *uobj; 3798 struct vm_amap *amap; 3799 struct vm_anon *anon; 3800 struct vm_page *pg; 3801 vaddr_t offset; 3802 vsize_t size; 3803 voff_t uoff; 3804 int error, refs; 3805 UVMHIST_FUNC(__func__); 3806 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,flags=%#jx)", 3807 (uintptr_t)map, start, end, flags); 3808 3809 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3810 (PGO_FREE|PGO_DEACTIVATE)); 3811 3812 vm_map_lock_read(map); 3813 VM_MAP_RANGE_CHECK(map, start, end); 3814 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3815 vm_map_unlock_read(map); 3816 return EFAULT; 3817 } 3818 3819 /* 3820 * Make a first pass to check for holes and wiring problems. 3821 */ 3822 3823 for (current = entry; current->start < end; current = current->next) { 3824 if (UVM_ET_ISSUBMAP(current)) { 3825 vm_map_unlock_read(map); 3826 return EINVAL; 3827 } 3828 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3829 vm_map_unlock_read(map); 3830 return EBUSY; 3831 } 3832 if (end <= current->end) { 3833 break; 3834 } 3835 if (current->end != current->next->start) { 3836 vm_map_unlock_read(map); 3837 return EFAULT; 3838 } 3839 } 3840 3841 error = 0; 3842 for (current = entry; start < end; current = current->next) { 3843 amap = current->aref.ar_amap; /* upper layer */ 3844 uobj = current->object.uvm_obj; /* lower layer */ 3845 KASSERT(start >= current->start); 3846 3847 /* 3848 * No amap cleaning necessary if: 3849 * 3850 * (1) There's no amap. 3851 * 3852 * (2) We're not deactivating or freeing pages. 3853 */ 3854 3855 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3856 goto flush_object; 3857 3858 offset = start - current->start; 3859 size = MIN(end, current->end) - start; 3860 3861 amap_lock(amap, RW_WRITER); 3862 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3863 anon = amap_lookup(¤t->aref, offset); 3864 if (anon == NULL) 3865 continue; 3866 3867 KASSERT(anon->an_lock == amap->am_lock); 3868 pg = anon->an_page; 3869 if (pg == NULL) { 3870 continue; 3871 } 3872 if (pg->flags & PG_BUSY) { 3873 continue; 3874 } 3875 3876 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 3877 3878 /* 3879 * In these first 3 cases, we just deactivate the page. 3880 */ 3881 3882 case PGO_CLEANIT|PGO_FREE: 3883 case PGO_CLEANIT|PGO_DEACTIVATE: 3884 case PGO_DEACTIVATE: 3885 deactivate_it: 3886 /* 3887 * skip the page if it's loaned or wired, 3888 * since it shouldn't be on a paging queue 3889 * at all in these cases. 3890 */ 3891 3892 if (pg->loan_count != 0 || 3893 pg->wire_count != 0) { 3894 continue; 3895 } 3896 KASSERT(pg->uanon == anon); 3897 uvm_pagelock(pg); 3898 uvm_pagedeactivate(pg); 3899 uvm_pageunlock(pg); 3900 continue; 3901 3902 case PGO_FREE: 3903 3904 /* 3905 * If there are multiple references to 3906 * the amap, just deactivate the page. 3907 */ 3908 3909 if (amap_refs(amap) > 1) 3910 goto deactivate_it; 3911 3912 /* skip the page if it's wired */ 3913 if (pg->wire_count != 0) { 3914 continue; 3915 } 3916 amap_unadd(¤t->aref, offset); 3917 refs = --anon->an_ref; 3918 if (refs == 0) { 3919 uvm_anfree(anon); 3920 } 3921 continue; 3922 } 3923 } 3924 amap_unlock(amap); 3925 3926 flush_object: 3927 /* 3928 * flush pages if we've got a valid backing object. 3929 * note that we must always clean object pages before 3930 * freeing them since otherwise we could reveal stale 3931 * data from files. 3932 */ 3933 3934 uoff = current->offset + (start - current->start); 3935 size = MIN(end, current->end) - start; 3936 if (uobj != NULL) { 3937 rw_enter(uobj->vmobjlock, RW_WRITER); 3938 if (uobj->pgops->pgo_put != NULL) 3939 error = (uobj->pgops->pgo_put)(uobj, uoff, 3940 uoff + size, flags | PGO_CLEANIT); 3941 else 3942 error = 0; 3943 } 3944 start += size; 3945 } 3946 vm_map_unlock_read(map); 3947 return (error); 3948 } 3949 3950 3951 /* 3952 * uvm_map_checkprot: check protection in map 3953 * 3954 * => must allow specified protection in a fully allocated region. 3955 * => map must be read or write locked by caller. 3956 */ 3957 3958 bool 3959 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 3960 vm_prot_t protection) 3961 { 3962 struct vm_map_entry *entry; 3963 struct vm_map_entry *tmp_entry; 3964 3965 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 3966 return (false); 3967 } 3968 entry = tmp_entry; 3969 while (start < end) { 3970 if (entry == &map->header) { 3971 return (false); 3972 } 3973 3974 /* 3975 * no holes allowed 3976 */ 3977 3978 if (start < entry->start) { 3979 return (false); 3980 } 3981 3982 /* 3983 * check protection associated with entry 3984 */ 3985 3986 if ((entry->protection & protection) != protection) { 3987 return (false); 3988 } 3989 start = entry->end; 3990 entry = entry->next; 3991 } 3992 return (true); 3993 } 3994 3995 /* 3996 * uvmspace_alloc: allocate a vmspace structure. 3997 * 3998 * - structure includes vm_map and pmap 3999 * - XXX: no locking on this structure 4000 * - refcnt set to 1, rest must be init'd by caller 4001 */ 4002 struct vmspace * 4003 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax, bool topdown) 4004 { 4005 struct vmspace *vm; 4006 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4007 4008 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4009 uvmspace_init(vm, NULL, vmin, vmax, topdown); 4010 UVMHIST_LOG(maphist,"<- done (vm=%#jx)", (uintptr_t)vm, 0, 0, 0); 4011 return (vm); 4012 } 4013 4014 /* 4015 * uvmspace_init: initialize a vmspace structure. 4016 * 4017 * - XXX: no locking on this structure 4018 * - refcnt set to 1, rest must be init'd by caller 4019 */ 4020 void 4021 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, 4022 vaddr_t vmax, bool topdown) 4023 { 4024 UVMHIST_FUNC(__func__); 4025 UVMHIST_CALLARGS(maphist, "(vm=%#jx, pmap=%#jx, vmin=%#jx, vmax=%#jx", 4026 (uintptr_t)vm, (uintptr_t)pmap, vmin, vmax); 4027 UVMHIST_LOG(maphist, " topdown=%ju)", topdown, 0, 0, 0); 4028 4029 memset(vm, 0, sizeof(*vm)); 4030 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4031 | (topdown ? VM_MAP_TOPDOWN : 0) 4032 ); 4033 if (pmap) 4034 pmap_reference(pmap); 4035 else 4036 pmap = pmap_create(); 4037 vm->vm_map.pmap = pmap; 4038 vm->vm_refcnt = 1; 4039 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4040 } 4041 4042 /* 4043 * uvmspace_share: share a vmspace between two processes 4044 * 4045 * - used for vfork, threads(?) 4046 */ 4047 4048 void 4049 uvmspace_share(struct proc *p1, struct proc *p2) 4050 { 4051 4052 uvmspace_addref(p1->p_vmspace); 4053 p2->p_vmspace = p1->p_vmspace; 4054 } 4055 4056 #if 0 4057 4058 /* 4059 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4060 * 4061 * - XXX: no locking on vmspace 4062 */ 4063 4064 void 4065 uvmspace_unshare(struct lwp *l) 4066 { 4067 struct proc *p = l->l_proc; 4068 struct vmspace *nvm, *ovm = p->p_vmspace; 4069 4070 if (ovm->vm_refcnt == 1) 4071 /* nothing to do: vmspace isn't shared in the first place */ 4072 return; 4073 4074 /* make a new vmspace, still holding old one */ 4075 nvm = uvmspace_fork(ovm); 4076 4077 kpreempt_disable(); 4078 pmap_deactivate(l); /* unbind old vmspace */ 4079 p->p_vmspace = nvm; 4080 pmap_activate(l); /* switch to new vmspace */ 4081 kpreempt_enable(); 4082 4083 uvmspace_free(ovm); /* drop reference to old vmspace */ 4084 } 4085 4086 #endif 4087 4088 4089 /* 4090 * uvmspace_spawn: a new process has been spawned and needs a vmspace 4091 */ 4092 4093 void 4094 uvmspace_spawn(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4095 { 4096 struct proc *p = l->l_proc; 4097 struct vmspace *nvm; 4098 4099 #ifdef __HAVE_CPU_VMSPACE_EXEC 4100 cpu_vmspace_exec(l, start, end); 4101 #endif 4102 4103 nvm = uvmspace_alloc(start, end, topdown); 4104 kpreempt_disable(); 4105 p->p_vmspace = nvm; 4106 pmap_activate(l); 4107 kpreempt_enable(); 4108 } 4109 4110 /* 4111 * uvmspace_exec: the process wants to exec a new program 4112 */ 4113 4114 void 4115 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown) 4116 { 4117 struct proc *p = l->l_proc; 4118 struct vmspace *nvm, *ovm = p->p_vmspace; 4119 struct vm_map *map; 4120 int flags; 4121 4122 KASSERT(ovm != NULL); 4123 #ifdef __HAVE_CPU_VMSPACE_EXEC 4124 cpu_vmspace_exec(l, start, end); 4125 #endif 4126 4127 map = &ovm->vm_map; 4128 /* 4129 * see if more than one process is using this vmspace... 4130 */ 4131 4132 if (ovm->vm_refcnt == 1 4133 && topdown == ((ovm->vm_map.flags & VM_MAP_TOPDOWN) != 0)) { 4134 4135 /* 4136 * if p is the only process using its vmspace then we can safely 4137 * recycle that vmspace for the program that is being exec'd. 4138 * But only if TOPDOWN matches the requested value for the new 4139 * vm space! 4140 */ 4141 4142 /* 4143 * SYSV SHM semantics require us to kill all segments on an exec 4144 */ 4145 if (uvm_shmexit && ovm->vm_shm) 4146 (*uvm_shmexit)(ovm); 4147 4148 /* 4149 * POSIX 1003.1b -- "lock future mappings" is revoked 4150 * when a process execs another program image. 4151 */ 4152 4153 map->flags &= ~VM_MAP_WIREFUTURE; 4154 4155 /* 4156 * now unmap the old program. 4157 * 4158 * XXX set VM_MAP_DYING for the duration, so pmap_update() 4159 * is not called until the pmap has been totally cleared out 4160 * after pmap_remove_all(), or it can confuse some pmap 4161 * implementations. it would be nice to handle this by 4162 * deferring the pmap_update() while it is known the address 4163 * space is not visible to any user LWP other than curlwp, 4164 * but there isn't an elegant way of inferring that right 4165 * now. 4166 */ 4167 4168 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0; 4169 map->flags |= VM_MAP_DYING; 4170 uvm_unmap1(map, vm_map_min(map), vm_map_max(map), flags); 4171 map->flags &= ~VM_MAP_DYING; 4172 pmap_update(map->pmap); 4173 KASSERT(map->header.prev == &map->header); 4174 KASSERT(map->nentries == 0); 4175 4176 /* 4177 * resize the map 4178 */ 4179 4180 vm_map_setmin(map, start); 4181 vm_map_setmax(map, end); 4182 } else { 4183 4184 /* 4185 * p's vmspace is being shared, so we can't reuse it for p since 4186 * it is still being used for others. allocate a new vmspace 4187 * for p 4188 */ 4189 4190 nvm = uvmspace_alloc(start, end, topdown); 4191 4192 /* 4193 * install new vmspace and drop our ref to the old one. 4194 */ 4195 4196 kpreempt_disable(); 4197 pmap_deactivate(l); 4198 p->p_vmspace = nvm; 4199 pmap_activate(l); 4200 kpreempt_enable(); 4201 4202 uvmspace_free(ovm); 4203 } 4204 } 4205 4206 /* 4207 * uvmspace_addref: add a reference to a vmspace. 4208 */ 4209 4210 void 4211 uvmspace_addref(struct vmspace *vm) 4212 { 4213 4214 KASSERT((vm->vm_map.flags & VM_MAP_DYING) == 0); 4215 KASSERT(vm->vm_refcnt > 0); 4216 atomic_inc_uint(&vm->vm_refcnt); 4217 } 4218 4219 /* 4220 * uvmspace_free: free a vmspace data structure 4221 */ 4222 4223 void 4224 uvmspace_free(struct vmspace *vm) 4225 { 4226 struct vm_map_entry *dead_entries; 4227 struct vm_map *map = &vm->vm_map; 4228 int flags; 4229 4230 UVMHIST_FUNC(__func__); 4231 UVMHIST_CALLARGS(maphist,"(vm=%#jx) ref=%jd", (uintptr_t)vm, 4232 vm->vm_refcnt, 0, 0); 4233 if (atomic_dec_uint_nv(&vm->vm_refcnt) > 0) 4234 return; 4235 4236 /* 4237 * at this point, there should be no other references to the map. 4238 * delete all of the mappings, then destroy the pmap. 4239 */ 4240 4241 map->flags |= VM_MAP_DYING; 4242 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0; 4243 4244 /* Get rid of any SYSV shared memory segments. */ 4245 if (uvm_shmexit && vm->vm_shm != NULL) 4246 (*uvm_shmexit)(vm); 4247 4248 if (map->nentries) { 4249 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4250 &dead_entries, flags); 4251 if (dead_entries != NULL) 4252 uvm_unmap_detach(dead_entries, 0); 4253 } 4254 KASSERT(map->nentries == 0); 4255 KASSERT(map->size == 0); 4256 4257 mutex_destroy(&map->misc_lock); 4258 rw_destroy(&map->lock); 4259 cv_destroy(&map->cv); 4260 pmap_destroy(map->pmap); 4261 pool_cache_put(&uvm_vmspace_cache, vm); 4262 } 4263 4264 static struct vm_map_entry * 4265 uvm_mapent_clone(struct vm_map *new_map, struct vm_map_entry *old_entry, 4266 int flags) 4267 { 4268 struct vm_map_entry *new_entry; 4269 4270 new_entry = uvm_mapent_alloc(new_map, 0); 4271 /* old_entry -> new_entry */ 4272 uvm_mapent_copy(old_entry, new_entry); 4273 4274 /* new pmap has nothing wired in it */ 4275 new_entry->wired_count = 0; 4276 4277 /* 4278 * gain reference to object backing the map (can't 4279 * be a submap, already checked this case). 4280 */ 4281 4282 if (new_entry->aref.ar_amap) 4283 uvm_map_reference_amap(new_entry, flags); 4284 4285 if (new_entry->object.uvm_obj && 4286 new_entry->object.uvm_obj->pgops->pgo_reference) 4287 new_entry->object.uvm_obj->pgops->pgo_reference( 4288 new_entry->object.uvm_obj); 4289 4290 /* insert entry at end of new_map's entry list */ 4291 uvm_map_entry_link(new_map, new_map->header.prev, 4292 new_entry); 4293 4294 return new_entry; 4295 } 4296 4297 /* 4298 * share the mapping: this means we want the old and 4299 * new entries to share amaps and backing objects. 4300 */ 4301 static void 4302 uvm_mapent_forkshared(struct vm_map *new_map, struct vm_map *old_map, 4303 struct vm_map_entry *old_entry) 4304 { 4305 /* 4306 * if the old_entry needs a new amap (due to prev fork) 4307 * then we need to allocate it now so that we have 4308 * something we own to share with the new_entry. [in 4309 * other words, we need to clear needs_copy] 4310 */ 4311 4312 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4313 /* get our own amap, clears needs_copy */ 4314 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4315 0, 0); 4316 /* XXXCDC: WAITOK??? */ 4317 } 4318 4319 uvm_mapent_clone(new_map, old_entry, AMAP_SHARED); 4320 } 4321 4322 4323 static void 4324 uvm_mapent_forkcopy(struct vm_map *new_map, struct vm_map *old_map, 4325 struct vm_map_entry *old_entry) 4326 { 4327 struct vm_map_entry *new_entry; 4328 4329 /* 4330 * copy-on-write the mapping (using mmap's 4331 * MAP_PRIVATE semantics) 4332 * 4333 * allocate new_entry, adjust reference counts. 4334 * (note that new references are read-only). 4335 */ 4336 4337 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4338 4339 new_entry->etype |= 4340 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4341 4342 /* 4343 * the new entry will need an amap. it will either 4344 * need to be copied from the old entry or created 4345 * from scratch (if the old entry does not have an 4346 * amap). can we defer this process until later 4347 * (by setting "needs_copy") or do we need to copy 4348 * the amap now? 4349 * 4350 * we must copy the amap now if any of the following 4351 * conditions hold: 4352 * 1. the old entry has an amap and that amap is 4353 * being shared. this means that the old (parent) 4354 * process is sharing the amap with another 4355 * process. if we do not clear needs_copy here 4356 * we will end up in a situation where both the 4357 * parent and child process are refering to the 4358 * same amap with "needs_copy" set. if the 4359 * parent write-faults, the fault routine will 4360 * clear "needs_copy" in the parent by allocating 4361 * a new amap. this is wrong because the 4362 * parent is supposed to be sharing the old amap 4363 * and the new amap will break that. 4364 * 4365 * 2. if the old entry has an amap and a non-zero 4366 * wire count then we are going to have to call 4367 * amap_cow_now to avoid page faults in the 4368 * parent process. since amap_cow_now requires 4369 * "needs_copy" to be clear we might as well 4370 * clear it here as well. 4371 * 4372 */ 4373 4374 if (old_entry->aref.ar_amap != NULL) { 4375 if ((amap_flags(old_entry->aref.ar_amap) & AMAP_SHARED) != 0 || 4376 VM_MAPENT_ISWIRED(old_entry)) { 4377 4378 amap_copy(new_map, new_entry, 4379 AMAP_COPY_NOCHUNK, 0, 0); 4380 /* XXXCDC: M_WAITOK ... ok? */ 4381 } 4382 } 4383 4384 /* 4385 * if the parent's entry is wired down, then the 4386 * parent process does not want page faults on 4387 * access to that memory. this means that we 4388 * cannot do copy-on-write because we can't write 4389 * protect the old entry. in this case we 4390 * resolve all copy-on-write faults now, using 4391 * amap_cow_now. note that we have already 4392 * allocated any needed amap (above). 4393 */ 4394 4395 if (VM_MAPENT_ISWIRED(old_entry)) { 4396 4397 /* 4398 * resolve all copy-on-write faults now 4399 * (note that there is nothing to do if 4400 * the old mapping does not have an amap). 4401 */ 4402 if (old_entry->aref.ar_amap) 4403 amap_cow_now(new_map, new_entry); 4404 4405 } else { 4406 /* 4407 * setup mappings to trigger copy-on-write faults 4408 * we must write-protect the parent if it has 4409 * an amap and it is not already "needs_copy"... 4410 * if it is already "needs_copy" then the parent 4411 * has already been write-protected by a previous 4412 * fork operation. 4413 */ 4414 if (old_entry->aref.ar_amap && 4415 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4416 if (old_entry->max_protection & VM_PROT_WRITE) { 4417 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */ 4418 uvm_map_lock_entry(old_entry, RW_WRITER); 4419 #else 4420 uvm_map_lock_entry(old_entry, RW_READER); 4421 #endif 4422 pmap_protect(old_map->pmap, 4423 old_entry->start, old_entry->end, 4424 old_entry->protection & ~VM_PROT_WRITE); 4425 uvm_map_unlock_entry(old_entry); 4426 } 4427 old_entry->etype |= UVM_ET_NEEDSCOPY; 4428 } 4429 } 4430 } 4431 4432 /* 4433 * zero the mapping: the new entry will be zero initialized 4434 */ 4435 static void 4436 uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map, 4437 struct vm_map_entry *old_entry) 4438 { 4439 struct vm_map_entry *new_entry; 4440 4441 new_entry = uvm_mapent_clone(new_map, old_entry, 0); 4442 4443 new_entry->etype |= 4444 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4445 4446 if (new_entry->aref.ar_amap) { 4447 uvm_map_unreference_amap(new_entry, 0); 4448 new_entry->aref.ar_pageoff = 0; 4449 new_entry->aref.ar_amap = NULL; 4450 } 4451 4452 if (UVM_ET_ISOBJ(new_entry)) { 4453 if (new_entry->object.uvm_obj->pgops->pgo_detach) 4454 new_entry->object.uvm_obj->pgops->pgo_detach( 4455 new_entry->object.uvm_obj); 4456 new_entry->object.uvm_obj = NULL; 4457 new_entry->etype &= ~UVM_ET_OBJ; 4458 } 4459 } 4460 4461 /* 4462 * F O R K - m a i n e n t r y p o i n t 4463 */ 4464 /* 4465 * uvmspace_fork: fork a process' main map 4466 * 4467 * => create a new vmspace for child process from parent. 4468 * => parent's map must not be locked. 4469 */ 4470 4471 struct vmspace * 4472 uvmspace_fork(struct vmspace *vm1) 4473 { 4474 struct vmspace *vm2; 4475 struct vm_map *old_map = &vm1->vm_map; 4476 struct vm_map *new_map; 4477 struct vm_map_entry *old_entry; 4478 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4479 4480 vm_map_lock(old_map); 4481 4482 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map), 4483 vm1->vm_map.flags & VM_MAP_TOPDOWN); 4484 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4485 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4486 new_map = &vm2->vm_map; /* XXX */ 4487 4488 old_entry = old_map->header.next; 4489 new_map->size = old_map->size; 4490 4491 /* 4492 * go entry-by-entry 4493 */ 4494 4495 while (old_entry != &old_map->header) { 4496 4497 /* 4498 * first, some sanity checks on the old entry 4499 */ 4500 4501 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4502 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4503 !UVM_ET_ISNEEDSCOPY(old_entry)); 4504 4505 switch (old_entry->inheritance) { 4506 case MAP_INHERIT_NONE: 4507 /* 4508 * drop the mapping, modify size 4509 */ 4510 new_map->size -= old_entry->end - old_entry->start; 4511 break; 4512 4513 case MAP_INHERIT_SHARE: 4514 uvm_mapent_forkshared(new_map, old_map, old_entry); 4515 break; 4516 4517 case MAP_INHERIT_COPY: 4518 uvm_mapent_forkcopy(new_map, old_map, old_entry); 4519 break; 4520 4521 case MAP_INHERIT_ZERO: 4522 uvm_mapent_forkzero(new_map, old_map, old_entry); 4523 break; 4524 default: 4525 KASSERT(0); 4526 break; 4527 } 4528 old_entry = old_entry->next; 4529 } 4530 4531 pmap_update(old_map->pmap); 4532 vm_map_unlock(old_map); 4533 4534 if (uvm_shmfork && vm1->vm_shm) 4535 (*uvm_shmfork)(vm1, vm2); 4536 4537 #ifdef PMAP_FORK 4538 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4539 #endif 4540 4541 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4542 return (vm2); 4543 } 4544 4545 4546 /* 4547 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4548 * 4549 * => called with map locked. 4550 * => return non zero if successfully merged. 4551 */ 4552 4553 int 4554 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4555 { 4556 struct uvm_object *uobj; 4557 struct vm_map_entry *next; 4558 struct vm_map_entry *prev; 4559 vsize_t size; 4560 int merged = 0; 4561 bool copying; 4562 int newetype; 4563 4564 if (entry->aref.ar_amap != NULL) { 4565 return 0; 4566 } 4567 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4568 return 0; 4569 } 4570 4571 uobj = entry->object.uvm_obj; 4572 size = entry->end - entry->start; 4573 copying = (flags & UVM_MERGE_COPYING) != 0; 4574 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4575 4576 next = entry->next; 4577 if (next != &map->header && 4578 next->start == entry->end && 4579 ((copying && next->aref.ar_amap != NULL && 4580 amap_refs(next->aref.ar_amap) == 1) || 4581 (!copying && next->aref.ar_amap == NULL)) && 4582 UVM_ET_ISCOMPATIBLE(next, newetype, 4583 uobj, entry->flags, entry->protection, 4584 entry->max_protection, entry->inheritance, entry->advice, 4585 entry->wired_count) && 4586 (uobj == NULL || entry->offset + size == next->offset)) { 4587 int error; 4588 4589 if (copying) { 4590 error = amap_extend(next, size, 4591 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4592 } else { 4593 error = 0; 4594 } 4595 if (error == 0) { 4596 if (uobj) { 4597 if (uobj->pgops->pgo_detach) { 4598 uobj->pgops->pgo_detach(uobj); 4599 } 4600 } 4601 4602 entry->end = next->end; 4603 clear_hints(map, next); 4604 uvm_map_entry_unlink(map, next); 4605 if (copying) { 4606 entry->aref = next->aref; 4607 entry->etype &= ~UVM_ET_NEEDSCOPY; 4608 } 4609 uvm_map_check(map, "trymerge forwardmerge"); 4610 uvm_mapent_free(next); 4611 merged++; 4612 } 4613 } 4614 4615 prev = entry->prev; 4616 if (prev != &map->header && 4617 prev->end == entry->start && 4618 ((copying && !merged && prev->aref.ar_amap != NULL && 4619 amap_refs(prev->aref.ar_amap) == 1) || 4620 (!copying && prev->aref.ar_amap == NULL)) && 4621 UVM_ET_ISCOMPATIBLE(prev, newetype, 4622 uobj, entry->flags, entry->protection, 4623 entry->max_protection, entry->inheritance, entry->advice, 4624 entry->wired_count) && 4625 (uobj == NULL || 4626 prev->offset + prev->end - prev->start == entry->offset)) { 4627 int error; 4628 4629 if (copying) { 4630 error = amap_extend(prev, size, 4631 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 4632 } else { 4633 error = 0; 4634 } 4635 if (error == 0) { 4636 if (uobj) { 4637 if (uobj->pgops->pgo_detach) { 4638 uobj->pgops->pgo_detach(uobj); 4639 } 4640 entry->offset = prev->offset; 4641 } 4642 4643 entry->start = prev->start; 4644 clear_hints(map, prev); 4645 uvm_map_entry_unlink(map, prev); 4646 if (copying) { 4647 entry->aref = prev->aref; 4648 entry->etype &= ~UVM_ET_NEEDSCOPY; 4649 } 4650 uvm_map_check(map, "trymerge backmerge"); 4651 uvm_mapent_free(prev); 4652 merged++; 4653 } 4654 } 4655 4656 return merged; 4657 } 4658 4659 /* 4660 * uvm_map_setup: init map 4661 * 4662 * => map must not be in service yet. 4663 */ 4664 4665 void 4666 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 4667 { 4668 4669 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 4670 map->header.next = map->header.prev = &map->header; 4671 map->nentries = 0; 4672 map->size = 0; 4673 map->ref_count = 1; 4674 vm_map_setmin(map, vmin); 4675 vm_map_setmax(map, vmax); 4676 map->flags = flags; 4677 map->first_free = &map->header; 4678 map->hint = &map->header; 4679 map->timestamp = 0; 4680 map->busy = NULL; 4681 4682 rw_init(&map->lock); 4683 cv_init(&map->cv, "vm_map"); 4684 mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE); 4685 } 4686 4687 /* 4688 * U N M A P - m a i n e n t r y p o i n t 4689 */ 4690 4691 /* 4692 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 4693 * 4694 * => caller must check alignment and size 4695 * => map must be unlocked (we will lock it) 4696 * => flags is UVM_FLAG_QUANTUM or 0. 4697 */ 4698 4699 void 4700 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 4701 { 4702 struct vm_map_entry *dead_entries; 4703 UVMHIST_FUNC(__func__); 4704 UVMHIST_CALLARGS(maphist, " (map=%#jx, start=%#jx, end=%#jx)", 4705 (uintptr_t)map, start, end, 0); 4706 4707 KASSERTMSG(start < end, 4708 "%s: map %p: start %#jx < end %#jx", __func__, map, 4709 (uintmax_t)start, (uintmax_t)end); 4710 if (map == kernel_map) { 4711 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 4712 } 4713 4714 /* 4715 * work now done by helper functions. wipe the pmap's and then 4716 * detach from the dead entries... 4717 */ 4718 vm_map_lock(map); 4719 uvm_unmap_remove(map, start, end, &dead_entries, flags); 4720 vm_map_unlock(map); 4721 4722 if (dead_entries != NULL) 4723 uvm_unmap_detach(dead_entries, 0); 4724 4725 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 4726 } 4727 4728 4729 /* 4730 * uvm_map_reference: add reference to a map 4731 * 4732 * => map need not be locked 4733 */ 4734 4735 void 4736 uvm_map_reference(struct vm_map *map) 4737 { 4738 4739 atomic_inc_uint(&map->ref_count); 4740 } 4741 4742 void 4743 uvm_map_lock_entry(struct vm_map_entry *entry, krw_t op) 4744 { 4745 4746 if (entry->aref.ar_amap != NULL) { 4747 amap_lock(entry->aref.ar_amap, op); 4748 } 4749 if (UVM_ET_ISOBJ(entry)) { 4750 rw_enter(entry->object.uvm_obj->vmobjlock, op); 4751 } 4752 } 4753 4754 void 4755 uvm_map_unlock_entry(struct vm_map_entry *entry) 4756 { 4757 4758 if (UVM_ET_ISOBJ(entry)) { 4759 rw_exit(entry->object.uvm_obj->vmobjlock); 4760 } 4761 if (entry->aref.ar_amap != NULL) { 4762 amap_unlock(entry->aref.ar_amap); 4763 } 4764 } 4765 4766 #define UVM_VOADDR_TYPE_MASK 0x3UL 4767 #define UVM_VOADDR_TYPE_UOBJ 0x1UL 4768 #define UVM_VOADDR_TYPE_ANON 0x2UL 4769 #define UVM_VOADDR_OBJECT_MASK ~UVM_VOADDR_TYPE_MASK 4770 4771 #define UVM_VOADDR_GET_TYPE(voa) \ 4772 ((voa)->object & UVM_VOADDR_TYPE_MASK) 4773 #define UVM_VOADDR_GET_OBJECT(voa) \ 4774 ((voa)->object & UVM_VOADDR_OBJECT_MASK) 4775 #define UVM_VOADDR_SET_OBJECT(voa, obj, type) \ 4776 do { \ 4777 KASSERT(((uintptr_t)(obj) & UVM_VOADDR_TYPE_MASK) == 0); \ 4778 (voa)->object = ((uintptr_t)(obj)) | (type); \ 4779 } while (/*CONSTCOND*/0) 4780 4781 #define UVM_VOADDR_GET_UOBJ(voa) \ 4782 ((struct uvm_object *)UVM_VOADDR_GET_OBJECT(voa)) 4783 #define UVM_VOADDR_SET_UOBJ(voa, uobj) \ 4784 UVM_VOADDR_SET_OBJECT(voa, uobj, UVM_VOADDR_TYPE_UOBJ) 4785 4786 #define UVM_VOADDR_GET_ANON(voa) \ 4787 ((struct vm_anon *)UVM_VOADDR_GET_OBJECT(voa)) 4788 #define UVM_VOADDR_SET_ANON(voa, anon) \ 4789 UVM_VOADDR_SET_OBJECT(voa, anon, UVM_VOADDR_TYPE_ANON) 4790 4791 /* 4792 * uvm_voaddr_acquire: returns the virtual object address corresponding 4793 * to the specified virtual address. 4794 * 4795 * => resolves COW so the true page identity is tracked. 4796 * 4797 * => acquires a reference on the page's owner (uvm_object or vm_anon) 4798 */ 4799 bool 4800 uvm_voaddr_acquire(struct vm_map * const map, vaddr_t const va, 4801 struct uvm_voaddr * const voaddr) 4802 { 4803 struct vm_map_entry *entry; 4804 struct vm_anon *anon = NULL; 4805 bool result = false; 4806 bool exclusive = false; 4807 void (*unlock_fn)(struct vm_map *); 4808 4809 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist); 4810 UVMHIST_LOG(maphist,"(map=%#jx,va=%#jx)", (uintptr_t)map, va, 0, 0); 4811 4812 const vaddr_t start = trunc_page(va); 4813 const vaddr_t end = round_page(va+1); 4814 4815 lookup_again: 4816 if (__predict_false(exclusive)) { 4817 vm_map_lock(map); 4818 unlock_fn = vm_map_unlock; 4819 } else { 4820 vm_map_lock_read(map); 4821 unlock_fn = vm_map_unlock_read; 4822 } 4823 4824 if (__predict_false(!uvm_map_lookup_entry(map, start, &entry))) { 4825 unlock_fn(map); 4826 UVMHIST_LOG(maphist,"<- done (no entry)",0,0,0,0); 4827 return false; 4828 } 4829 4830 if (__predict_false(entry->protection == VM_PROT_NONE)) { 4831 unlock_fn(map); 4832 UVMHIST_LOG(maphist,"<- done (PROT_NONE)",0,0,0,0); 4833 return false; 4834 } 4835 4836 /* 4837 * We have a fast path for the common case of "no COW resolution 4838 * needed" whereby we have taken a read lock on the map and if 4839 * we don't encounter any need to create a vm_anon then great! 4840 * But if we do, we loop around again, instead taking an exclusive 4841 * lock so that we can perform the fault. 4842 * 4843 * In the event that we have to resolve the fault, we do nearly the 4844 * same work as uvm_map_pageable() does: 4845 * 4846 * 1: holding the write lock, we create any anonymous maps that need 4847 * to be created. however, we do NOT need to clip the map entries 4848 * in this case. 4849 * 4850 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 4851 * in the page (assuming the entry is not already wired). this 4852 * is done because we need the vm_anon to be present. 4853 */ 4854 if (__predict_true(!VM_MAPENT_ISWIRED(entry))) { 4855 4856 bool need_fault = false; 4857 4858 /* 4859 * perform the action of vm_map_lookup that need the 4860 * write lock on the map: create an anonymous map for 4861 * a copy-on-write region, or an anonymous map for 4862 * a zero-fill region. 4863 */ 4864 if (__predict_false(UVM_ET_ISSUBMAP(entry))) { 4865 unlock_fn(map); 4866 UVMHIST_LOG(maphist,"<- done (submap)",0,0,0,0); 4867 return false; 4868 } 4869 if (__predict_false(UVM_ET_ISNEEDSCOPY(entry) && 4870 ((entry->max_protection & VM_PROT_WRITE) || 4871 (entry->object.uvm_obj == NULL)))) { 4872 if (!exclusive) { 4873 /* need to take the slow path */ 4874 KASSERT(unlock_fn == vm_map_unlock_read); 4875 vm_map_unlock_read(map); 4876 exclusive = true; 4877 goto lookup_again; 4878 } 4879 need_fault = true; 4880 amap_copy(map, entry, 0, start, end); 4881 /* XXXCDC: wait OK? */ 4882 } 4883 4884 /* 4885 * do a quick check to see if the fault has already 4886 * been resolved to the upper layer. 4887 */ 4888 if (__predict_true(entry->aref.ar_amap != NULL && 4889 need_fault == false)) { 4890 amap_lock(entry->aref.ar_amap, RW_WRITER); 4891 anon = amap_lookup(&entry->aref, start - entry->start); 4892 if (__predict_true(anon != NULL)) { 4893 /* amap unlocked below */ 4894 goto found_anon; 4895 } 4896 amap_unlock(entry->aref.ar_amap); 4897 need_fault = true; 4898 } 4899 4900 /* 4901 * we predict this test as false because if we reach 4902 * this point, then we are likely dealing with a 4903 * shared memory region backed by a uvm_object, in 4904 * which case a fault to create the vm_anon is not 4905 * necessary. 4906 */ 4907 if (__predict_false(need_fault)) { 4908 if (exclusive) { 4909 vm_map_busy(map); 4910 vm_map_unlock(map); 4911 unlock_fn = vm_map_unbusy; 4912 } 4913 4914 if (uvm_fault_wire(map, start, end, 4915 entry->max_protection, 1)) { 4916 /* wiring failed */ 4917 unlock_fn(map); 4918 UVMHIST_LOG(maphist,"<- done (wire failed)", 4919 0,0,0,0); 4920 return false; 4921 } 4922 4923 /* 4924 * now that we have resolved the fault, we can unwire 4925 * the page. 4926 */ 4927 if (exclusive) { 4928 vm_map_lock(map); 4929 vm_map_unbusy(map); 4930 unlock_fn = vm_map_unlock; 4931 } 4932 4933 uvm_fault_unwire_locked(map, start, end); 4934 } 4935 } 4936 4937 /* check the upper layer */ 4938 if (entry->aref.ar_amap) { 4939 amap_lock(entry->aref.ar_amap, RW_WRITER); 4940 anon = amap_lookup(&entry->aref, start - entry->start); 4941 if (anon) { 4942 found_anon: KASSERT(anon->an_lock == entry->aref.ar_amap->am_lock); 4943 anon->an_ref++; 4944 rw_obj_hold(anon->an_lock); 4945 KASSERT(anon->an_ref != 0); 4946 UVM_VOADDR_SET_ANON(voaddr, anon); 4947 voaddr->offset = va & PAGE_MASK; 4948 result = true; 4949 } 4950 amap_unlock(entry->aref.ar_amap); 4951 } 4952 4953 /* check the lower layer */ 4954 if (!result && UVM_ET_ISOBJ(entry)) { 4955 struct uvm_object *uobj = entry->object.uvm_obj; 4956 4957 KASSERT(uobj != NULL); 4958 (*uobj->pgops->pgo_reference)(uobj); 4959 UVM_VOADDR_SET_UOBJ(voaddr, uobj); 4960 voaddr->offset = entry->offset + (va - entry->start); 4961 result = true; 4962 } 4963 4964 unlock_fn(map); 4965 4966 if (result) { 4967 UVMHIST_LOG(maphist, 4968 "<- done OK (type=%jd,owner=%#jx,offset=%#jx)", 4969 UVM_VOADDR_GET_TYPE(voaddr), 4970 UVM_VOADDR_GET_OBJECT(voaddr), 4971 voaddr->offset, 0); 4972 } else { 4973 UVMHIST_LOG(maphist,"<- done (failed)",0,0,0,0); 4974 } 4975 4976 return result; 4977 } 4978 4979 /* 4980 * uvm_voaddr_release: release the references held by the 4981 * vitual object address. 4982 */ 4983 void 4984 uvm_voaddr_release(struct uvm_voaddr * const voaddr) 4985 { 4986 4987 switch (UVM_VOADDR_GET_TYPE(voaddr)) { 4988 case UVM_VOADDR_TYPE_UOBJ: { 4989 struct uvm_object * const uobj = UVM_VOADDR_GET_UOBJ(voaddr); 4990 4991 KASSERT(uobj != NULL); 4992 KASSERT(uobj->pgops->pgo_detach != NULL); 4993 (*uobj->pgops->pgo_detach)(uobj); 4994 break; 4995 } 4996 case UVM_VOADDR_TYPE_ANON: { 4997 struct vm_anon * const anon = UVM_VOADDR_GET_ANON(voaddr); 4998 krwlock_t *lock; 4999 5000 KASSERT(anon != NULL); 5001 rw_enter((lock = anon->an_lock), RW_WRITER); 5002 KASSERT(anon->an_ref > 0); 5003 if (--anon->an_ref == 0) { 5004 uvm_anfree(anon); 5005 } 5006 rw_exit(lock); 5007 rw_obj_free(lock); 5008 break; 5009 } 5010 default: 5011 panic("uvm_voaddr_release: bad type"); 5012 } 5013 memset(voaddr, 0, sizeof(*voaddr)); 5014 } 5015 5016 /* 5017 * uvm_voaddr_compare: compare two uvm_voaddr objects. 5018 * 5019 * => memcmp() semantics 5020 */ 5021 int 5022 uvm_voaddr_compare(const struct uvm_voaddr * const voaddr1, 5023 const struct uvm_voaddr * const voaddr2) 5024 { 5025 const uintptr_t type1 = UVM_VOADDR_GET_TYPE(voaddr1); 5026 const uintptr_t type2 = UVM_VOADDR_GET_TYPE(voaddr2); 5027 5028 KASSERT(type1 == UVM_VOADDR_TYPE_UOBJ || 5029 type1 == UVM_VOADDR_TYPE_ANON); 5030 5031 KASSERT(type2 == UVM_VOADDR_TYPE_UOBJ || 5032 type2 == UVM_VOADDR_TYPE_ANON); 5033 5034 if (type1 < type2) 5035 return -1; 5036 if (type1 > type2) 5037 return 1; 5038 5039 const uintptr_t addr1 = UVM_VOADDR_GET_OBJECT(voaddr1); 5040 const uintptr_t addr2 = UVM_VOADDR_GET_OBJECT(voaddr2); 5041 5042 if (addr1 < addr2) 5043 return -1; 5044 if (addr1 > addr2) 5045 return 1; 5046 5047 if (voaddr1->offset < voaddr2->offset) 5048 return -1; 5049 if (voaddr1->offset > voaddr2->offset) 5050 return 1; 5051 5052 return 0; 5053 } 5054 5055 #if defined(DDB) || defined(DEBUGPRINT) 5056 5057 /* 5058 * uvm_map_printit: actually prints the map 5059 */ 5060 5061 void 5062 uvm_map_printit(struct vm_map *map, bool full, 5063 void (*pr)(const char *, ...)) 5064 { 5065 struct vm_map_entry *entry; 5066 5067 (*pr)("MAP %p: [%#lx->%#lx]\n", map, vm_map_min(map), 5068 vm_map_max(map)); 5069 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=%#x\n", 5070 map->nentries, map->size, map->ref_count, map->timestamp, 5071 map->flags); 5072 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 5073 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 5074 if (!full) 5075 return; 5076 for (entry = map->header.next; entry != &map->header; 5077 entry = entry->next) { 5078 (*pr)(" - %p: %#lx->%#lx: obj=%p/%#llx, amap=%p/%d\n", 5079 entry, entry->start, entry->end, entry->object.uvm_obj, 5080 (long long)entry->offset, entry->aref.ar_amap, 5081 entry->aref.ar_pageoff); 5082 (*pr)( 5083 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 5084 "wc=%d, adv=%d\n", 5085 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 5086 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 5087 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 5088 entry->protection, entry->max_protection, 5089 entry->inheritance, entry->wired_count, entry->advice); 5090 } 5091 } 5092 5093 void 5094 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 5095 { 5096 struct vm_map *map; 5097 5098 for (map = kernel_map;;) { 5099 struct vm_map_entry *entry; 5100 5101 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 5102 break; 5103 } 5104 (*pr)("%p is %p+%zu from VMMAP %p\n", 5105 (void *)addr, (void *)entry->start, 5106 (size_t)(addr - (uintptr_t)entry->start), map); 5107 if (!UVM_ET_ISSUBMAP(entry)) { 5108 break; 5109 } 5110 map = entry->object.sub_map; 5111 } 5112 } 5113 5114 #endif /* DDB || DEBUGPRINT */ 5115 5116 #ifndef __USER_VA0_IS_SAFE 5117 static int 5118 sysctl_user_va0_disable(SYSCTLFN_ARGS) 5119 { 5120 struct sysctlnode node; 5121 int t, error; 5122 5123 node = *rnode; 5124 node.sysctl_data = &t; 5125 t = user_va0_disable; 5126 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 5127 if (error || newp == NULL) 5128 return (error); 5129 5130 if (!t && user_va0_disable && 5131 kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MAP_VA_ZERO, 0, 5132 NULL, NULL, NULL)) 5133 return EPERM; 5134 5135 user_va0_disable = !!t; 5136 return 0; 5137 } 5138 #endif 5139 5140 static int 5141 fill_vmentry(struct lwp *l, struct proc *p, struct kinfo_vmentry *kve, 5142 struct vm_map *m, struct vm_map_entry *e) 5143 { 5144 #ifndef _RUMPKERNEL 5145 int error; 5146 5147 memset(kve, 0, sizeof(*kve)); 5148 KASSERT(e != NULL); 5149 if (UVM_ET_ISOBJ(e)) { 5150 struct uvm_object *uobj = e->object.uvm_obj; 5151 KASSERT(uobj != NULL); 5152 kve->kve_ref_count = uobj->uo_refs; 5153 kve->kve_count = uobj->uo_npages; 5154 if (UVM_OBJ_IS_VNODE(uobj)) { 5155 struct vattr va; 5156 struct vnode *vp = (struct vnode *)uobj; 5157 vn_lock(vp, LK_SHARED | LK_RETRY); 5158 error = VOP_GETATTR(vp, &va, l->l_cred); 5159 VOP_UNLOCK(vp); 5160 kve->kve_type = KVME_TYPE_VNODE; 5161 if (error == 0) { 5162 kve->kve_vn_size = vp->v_size; 5163 kve->kve_vn_type = (int)vp->v_type; 5164 kve->kve_vn_mode = va.va_mode; 5165 kve->kve_vn_rdev = va.va_rdev; 5166 kve->kve_vn_fileid = va.va_fileid; 5167 kve->kve_vn_fsid = va.va_fsid; 5168 error = vnode_to_path(kve->kve_path, 5169 sizeof(kve->kve_path) / 2, vp, l, p); 5170 #ifdef DIAGNOSTIC 5171 if (error) 5172 printf("%s: vp %p error %d\n", __func__, 5173 vp, error); 5174 #endif 5175 } 5176 } else if (UVM_OBJ_IS_KERN_OBJECT(uobj)) { 5177 kve->kve_type = KVME_TYPE_KERN; 5178 } else if (UVM_OBJ_IS_DEVICE(uobj)) { 5179 kve->kve_type = KVME_TYPE_DEVICE; 5180 } else if (UVM_OBJ_IS_AOBJ(uobj)) { 5181 kve->kve_type = KVME_TYPE_ANON; 5182 } else { 5183 kve->kve_type = KVME_TYPE_OBJECT; 5184 } 5185 } else if (UVM_ET_ISSUBMAP(e)) { 5186 struct vm_map *map = e->object.sub_map; 5187 KASSERT(map != NULL); 5188 kve->kve_ref_count = map->ref_count; 5189 kve->kve_count = map->nentries; 5190 kve->kve_type = KVME_TYPE_SUBMAP; 5191 } else 5192 kve->kve_type = KVME_TYPE_UNKNOWN; 5193 5194 kve->kve_start = e->start; 5195 kve->kve_end = e->end; 5196 kve->kve_offset = e->offset; 5197 kve->kve_wired_count = e->wired_count; 5198 kve->kve_inheritance = e->inheritance; 5199 kve->kve_attributes = 0; /* unused */ 5200 kve->kve_advice = e->advice; 5201 #define PROT(p) (((p) & VM_PROT_READ) ? KVME_PROT_READ : 0) | \ 5202 (((p) & VM_PROT_WRITE) ? KVME_PROT_WRITE : 0) | \ 5203 (((p) & VM_PROT_EXECUTE) ? KVME_PROT_EXEC : 0) 5204 kve->kve_protection = PROT(e->protection); 5205 kve->kve_max_protection = PROT(e->max_protection); 5206 kve->kve_flags |= (e->etype & UVM_ET_COPYONWRITE) 5207 ? KVME_FLAG_COW : 0; 5208 kve->kve_flags |= (e->etype & UVM_ET_NEEDSCOPY) 5209 ? KVME_FLAG_NEEDS_COPY : 0; 5210 kve->kve_flags |= (m->flags & VM_MAP_TOPDOWN) 5211 ? KVME_FLAG_GROWS_DOWN : KVME_FLAG_GROWS_UP; 5212 kve->kve_flags |= (m->flags & VM_MAP_PAGEABLE) 5213 ? KVME_FLAG_PAGEABLE : 0; 5214 #endif 5215 return 0; 5216 } 5217 5218 static int 5219 fill_vmentries(struct lwp *l, pid_t pid, u_int elem_size, void *oldp, 5220 size_t *oldlenp) 5221 { 5222 int error; 5223 struct proc *p; 5224 struct kinfo_vmentry *vme; 5225 struct vmspace *vm; 5226 struct vm_map *map; 5227 struct vm_map_entry *entry; 5228 char *dp; 5229 size_t count, vmesize; 5230 5231 if (elem_size == 0 || elem_size > 2 * sizeof(*vme)) 5232 return EINVAL; 5233 5234 if (oldp) { 5235 if (*oldlenp > 10UL * 1024UL * 1024UL) 5236 return E2BIG; 5237 count = *oldlenp / elem_size; 5238 if (count == 0) 5239 return ENOMEM; 5240 vmesize = count * sizeof(*vme); 5241 } else 5242 vmesize = 0; 5243 5244 if ((error = proc_find_locked(l, &p, pid)) != 0) 5245 return error; 5246 5247 vme = NULL; 5248 count = 0; 5249 5250 if ((error = proc_vmspace_getref(p, &vm)) != 0) 5251 goto out; 5252 5253 map = &vm->vm_map; 5254 vm_map_lock_read(map); 5255 5256 dp = oldp; 5257 if (oldp) 5258 vme = kmem_alloc(vmesize, KM_SLEEP); 5259 for (entry = map->header.next; entry != &map->header; 5260 entry = entry->next) { 5261 if (oldp && (dp - (char *)oldp) < vmesize) { 5262 error = fill_vmentry(l, p, &vme[count], map, entry); 5263 if (error) 5264 goto out; 5265 dp += elem_size; 5266 } 5267 count++; 5268 } 5269 vm_map_unlock_read(map); 5270 uvmspace_free(vm); 5271 5272 out: 5273 if (pid != -1) 5274 mutex_exit(p->p_lock); 5275 if (error == 0) { 5276 const u_int esize = uimin(sizeof(*vme), elem_size); 5277 dp = oldp; 5278 for (size_t i = 0; i < count; i++) { 5279 if (oldp && (dp - (char *)oldp) < vmesize) { 5280 error = sysctl_copyout(l, &vme[i], dp, esize); 5281 if (error) 5282 break; 5283 dp += elem_size; 5284 } else 5285 break; 5286 } 5287 count *= elem_size; 5288 if (oldp != NULL && *oldlenp < count) 5289 error = ENOSPC; 5290 *oldlenp = count; 5291 } 5292 if (vme) 5293 kmem_free(vme, vmesize); 5294 return error; 5295 } 5296 5297 static int 5298 sysctl_vmproc(SYSCTLFN_ARGS) 5299 { 5300 int error; 5301 5302 if (namelen == 1 && name[0] == CTL_QUERY) 5303 return (sysctl_query(SYSCTLFN_CALL(rnode))); 5304 5305 if (namelen == 0) 5306 return EINVAL; 5307 5308 switch (name[0]) { 5309 case VM_PROC_MAP: 5310 if (namelen != 3) 5311 return EINVAL; 5312 sysctl_unlock(); 5313 error = fill_vmentries(l, name[1], name[2], oldp, oldlenp); 5314 sysctl_relock(); 5315 return error; 5316 default: 5317 return EINVAL; 5318 } 5319 } 5320 5321 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5322 { 5323 5324 sysctl_createv(clog, 0, NULL, NULL, 5325 CTLFLAG_PERMANENT, 5326 CTLTYPE_STRUCT, "proc", 5327 SYSCTL_DESCR("Process vm information"), 5328 sysctl_vmproc, 0, NULL, 0, 5329 CTL_VM, VM_PROC, CTL_EOL); 5330 #ifndef __USER_VA0_IS_SAFE 5331 sysctl_createv(clog, 0, NULL, NULL, 5332 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5333 CTLTYPE_INT, "user_va0_disable", 5334 SYSCTL_DESCR("Disable VA 0"), 5335 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5336 CTL_VM, CTL_CREATE, CTL_EOL); 5337 #endif 5338 } 5339